For guys wondering why SOTAR won't give recommendations on BCG or barrel manufacturers, you're missing the point, which is that inspection-verification of individual components is more important than where the components came from. Yes, maybe certain manufacturers are more consistent, but no manufacturer is 100% perfect.
I think people would like to know who the more consistent manufacturers are. It's similar to an auto mechanic who knows which cars are more reliable, on average, and people asking so that they can have a higher chance of buying a more reliable car.
Yeah, but that's more $ in precision gauges then it would be to build 2 AR's. If "the point is to inspect the dimensions" it would seem better to use only calipers when possible or at least having the gauge diameters marked. Otherwise he is giving advice without giving advice, when he says "this BCM is an anomaly" makes me proud I went BCM.
@Justin if you watch enough of his videos, you will pick up on what manufacturers are "generally" in spec. If you read between the lines you will find the information you are searching for.
@@5jjt BCM, LMT, Toolcraft, Bootleg, KAC(proprietary though), these are some good ones. I personally run BCM BCGs and several uppers and I love them. They make a quality product at an affordable price. I think they produce a better rifle than Daniel Defense which is more expensive. IF you get a BCM lower(most BCMs I see are an Aero lower using a BCM upper, or some other brand of lower) you'll get a polished nickel coated trigger(so enhanced milspec essentially), a rifle that tends to be pretty well gassed, a good rail(though to be fair this is one area where DD might be superior) and a good barrel. DD just gives you a regular milspec trigger and their rifles are very commonly SERIOUSLY overgassed. I think they've gotten better about it more recently but they're still over gassed. I have a block 2 m4 upper from DD and its overgassed whereas I have a BCM 14.5(Both the DD block 2 m4 and BCM are pinned and welded) with midlength gas system and it was perfectly gassed right out of the box with military grade 5.56 using just a normal carbine weight buffer.
Watched about 5 minutes of this video and immediately subscribed. That knowledge of bolt stretching and cam pin issues is something that I may never have learned about in my life. Thanks for passing your knowledge on to people who want to learn.
I quickly learned after I found this channel I was suffering from a little bit of the "Dunning-Kruger" effect when it came to my knowledge on the AR platform. I believed that I knew a lot more than I actually did. He's doing people who really want to learn a great service and I would jump at a chance to learn from him in person. Just a great channel and a great resource, I've really learned a lot from him
As you were inspecting these two BCG's, a thought went through my mind. As popular of your channel has become, I would bet that you could sell bolt carriers with the SOTAR insignia etched onto them. I know it would interest me. Think about it, and try to find someone to do it for you. you have the business, designed a logo, you have merchandise, this would be one more thing to bring in income.
I’ve been waiting for a BCM bcg physical and it looks like BCM’s quality control (at least for the phosphate bcg) is fantastic as usual. I did have to send an upper back to them last week, it’s a MK2 BFH 11.5” that would not pass a 5.56 go gauge. After 1.5 days it was on its way back to me. I also have a MK2 BFH 14.5” pinned and welded and it passed perfectly fine. Thanks again for the awesome video. Still the best content on RUclips!!!
@ARcoholic ARcoholic Its an extra level of piece of mind if you're getting a brand new receiver for either a complete upper or a build I would say. Its friendlier for using an ambi charging handle for sure, cause the FA is moved a bit forward. That being said, if you already have a normal conventional upper receiver, dont feel as if you need to replace all of them with BCM Mk2s.
As the owner of two MK2’s and several mil spec BCM’s, I’ll take the MK2 over the mil spec any day. Where they relocated the shell deflector and forward assist, it gives you a lot more room to run offset iron sights. Also, in comparison it’s substantially more robust in critical areas and I find it visually more appealing than a normal upper. Just my two cents, hope it helps.
Parker Allison I want one so bad!! I just hope that when I get it, it’s good to go and doesn’t have any QC issues since I’ve heard some folks have had problems with their uppers due to the insane demand as of lately.
Love my BCM 14.5 mid. I got the enhanced light weight barrel and it just feels so wieldy. I was worried my groups would open up severely after long strings of fire but really they don't. Not enough to matter anyway.
Hey, new subscriber here! Would you be willing to make a video discussing what your standard modifications or changes to a BCG are and why you perform them? It'd be interesting to see your reasoning, as a newbie to this more involved aspect of firearms.
So maybe stick with the standard BCM bcg's. I actually have two of the ion bonded bcg's and I trust them almost exclusively. I've baught from Spikes, Noveske, Aero, and PSA for some of my builds an I usually find something off with all but the BCMs. Although after watching many of your videos on bcg's I've come to some new conclusions about stuff. For example I don't get ood coatings like nickel boron anymore. I also look for more tolerance issues beyond just the gas ring seal now to. Additionally I replace yfs fasiners almost immediately. So long story short your information is very helpful thank you.
I've seen 2 bad bcgs from bcm. One gas key broke loose at about 1200 rounds. 2nd was out of spec bolt itself. Ejector not moving freely inside bolt body. Bcm is just like everyone else, and have issues occasionally
@@Helibeaver Sure everyone has issues I get that. However what I meant was it's probably best to just save money and buy the regular bcg's instead of the ones with the fancy coatings. Possibly more chance the regular finishes are in spec since it's something that's been a known quantity for years.
I have a WMD NiBx BCG with around 1300rnds in an SBR and I have no coating issues. From what I've seen, not all coating/bondings are created equal, just like any BCG, barrel etc.
He deserves it for all the knowledge and awesome Tips he gives to the community! Things like checking your bolt catch spring with the weight of the bolt or if you’re field stripping your bcg you can put all of the parts and fit them all inside the groove on the charging handle. Those are only some of many tips you will gain from watching him work. It’s top tier stuff and I love it!
Having been a fan of the ar platform for many years, it is just since I found your channel that I can get the info needed to truly troubleshoot issues and figure out the root problems to troublesome guns. However finding a lot of the go, no go gauges you have is impossible.
Let’s be real. Some of the bolts are built by the same manufacture. Who knows unless you do your research. So each video gives a small look into the manufacturer. Medals. Ect. So much like a engine. How the medals mate. How they wear. I can’t get enough of these videos.
I like Centurion's Chrome Sandcutter Carrier and their dual ejector bolt. I saw SOTAR's examination of said carrier and that honestly just reinforced what I was already thinking.
Just found this channel over the past weekend. Great content and thank you for sharing. Just watched the UNISSUED U.S.G.I. M16/A1/A2 ARMORERS TOOL KIT video tonight, pretty cool stuff you are doing.
Another amazing video! Are there any blueprint books with dimensions and tolerances on these AR 15/ AR 10 components? I would love to own own a few of these. Any recommendations?
Both of my FN ARs, a 16" M4 and an 18" match grade sporter use both the extractor spring and (brown) insert. Theyve always ran flawlessly but i also added a blue O-ring. I have almost 16k rounds on the M4 and 13k rounds through the sporter without issue. Im actually amazed by both rifles. Not only are they consistently sub MOA accurate and 100% reliable but theyre both as durable as the proverbial hammer it seems. The barrels have lost perhaps 1/8" to 1/4" of accuracy at 100 yds though still can pull 5) rd groups of 1/2" when i do my part with their preferred loads. The BCGs look like brand new still. Just the slightest finish wear on the ends of the carrier rails. Ditto for the bolts. The finish wear on the lug faces are very slight and perfectly even. The extractors have a polished look at the leading edge of the case bevel but otherwise look new. Piston rings are still holding just like new and while clean and lubed and with the piston rings dead center of the gas ports, easily support the weight of the carrier + a standard aluminum Okay Surefeed G.I. magazine loaded with 3 to 4 green tip rounds (a field expedient method i use to determine BCG health) The cam pin still has 95% of its finish and fits snug with minimal play. I have noticed theres a bit more play side to side than front to back which is practically nill. And that brings me to my first of a few questions. If bolt stretch is the mechanism that generally causes the demise of a bolt (as far as cam pin/bolt tail is concerned), wouldnt the cam pin hole show more play in the front to back or axial direction (in line with firing pin) rather than side to side or laterally? Obviously i dont have all the gauges and tools to properly check wear but the fact that i can definitely detect more play in one direction over the other, is that a viable method to determine the health of the bolt and if not what does this finding suggest if anything? And finally, just how long should i expect these things to run and should i go ahead and replace anything as a precaution? Ive always heard a good chrome lined barrel will last 10k to 15k, a good bolt should be replaced at 5k as per Eugene Stoners suggestion. Im well beyond that and running just fine. What gives and what if anything should i replace? Thanks in advance for your reply if you do!
Chad do u have a top 5 suggested bcgs? I've never heard you mention your suggested bcg or barrel manufacturers. Would really appreciate your input with several options
@School of the American Rifle You have a lot of gauges that are clearly hard to come by. Do you have a list or reference somewhere that lists the dimensional tolerances for each of the checks you're performing? I recognize you don't need them if you have the gauges, but for a guy like me who has gauge pins, micrometers, etc. it would be helpful to have a list of tolerances. Thanks
Chad, I have two rifles built with that specific BCG from BCM and that is a nitride coated BCG and I have seen the same thing on mine. Also, you might want to mention why you put that mark on the roller pin. As I recall from your class, you said that roller pin should always be installed the same way, thus the mark.
I believe hes said in certain videos a lot of them he sells only to people who take his class, some are custom made for him and some you can buy from retailers
Totally! Assuming you can pay him to review your stuff or that only in classes? Either way, just do what SOLGW does and buy microbest BCGs then pay Chad to upgrade spring and inspect haha... (For the record they do apparently individual HPT & MPI their bolts)
Very curious about this one as bcm claims they 100% check every bolt including gauging boat tail, gas ring and shoulder etc … happy to see one brown down to this degree as they are considered and I believe want to be quality through and through as lives depend on their product
If they never let you down why do you keep having to purchase them, a collector I presume; makes me wonder about longevity, what's your highest round count?
You should check gas key alignment when gas tube is installed. There are no moving parts through the gas tube opening in the upper reciever. I understand why you do check it with gas tube out because machining could be off on upper.
Just found your videos were have you been my whole life lol. Maybe You have made a video on this topic. I just purchased a custom barrel by dead shot barrels in terrabon Oregon, great people good turn around, he cut my bolt to my barrel. What's your take on that? And is that an actual good functioning thing to have happen? Like your awesome opinion. I'm a engineer for 30 years and I knew there was a guy like you out there thats No bolt Carrier are alike and with all your jigs and tolerances. I knew that there were a lot of factors into one. Keep up the good work man. Thanks.
I've become kind of addicted to these videos. I've been putting together AR's for years, but I've never known the proper way to inspect the different parts. Thanks for making these. I do have one question, what is the significance of the parts having magnetism?
The reasoning behind the magnetism tests is for when you're shooting steel cased ammunition, as shavings can accumulate over time on the parts that do have magnetism and can cause issues in higher round counts
Great content!! I had a bolt that had 2 of the lugs sheer clean off while firing. What would cause this? I’ve asked many people but now I’ve found the wizard!
Heat (Long answer has to do with increased movement of electrons abd their tendency to "line up" their "spin") I'm sure harbor freight has a de-magnatizer (it's some substance that you rub the metal on, the composition of which is an excellent question for an inorganic chemist, I'm more organic (love me some nmr's and reaction mechanisms))
Great video, I learned a lot about maintaining my bcg. I have a carbon tool with firing pin cleaning hole and set of calipers. I just purchased a go/ no go gage set. In your opinion what would your next bcg tool to add? I can’t afford to purchase everything in your video all at once. Thanks for any input your willing to share.
My bcm bcg bolt came with the o ring on the spring plus another o ring in a bag for short barrel rifles. Should I remove the o ring if im just running a 16inch?
Hey their, you said you recommend tapco extractor spring, good place to order it from? And what would be a good camera for a normal everyday guy , only use it from time to time, and good place to buy one from, Thanks alot!
Love your vids! Can you please provide a vid on proper lubrication? Im always wondering how much oil I should be using in the trigger mech and such. Thanks!
Could you please get together a set of all the gauges that I would need to check a diamondback 300blkout, please? I have looked and am coming up empty-handed. I'll pay whatever it costs I'm asking you because I trust you completely after watching your videos!!!
I'll hopefully be starting gunsmithing in the fall/winter and I can put the gauges to good use I have a micrometer that is analog but I think I may get a digital version at some point
Im no expert, but i think he said in a previous video that if you use steel ammo sometimes small steel shavings from the ammo will stick to the magnetized parts and cause premature wear.
Parts can become magnetized in different machinery during manufacturing. Like if a mill vise or lathe chuck is magnetized, anything it holds could become magnetized.
Telescoping gauges and a caliper will get you most the dimensions unless its really small. It's overkill for a normal person to use all those bore gauges. You could easily spend hundreds getting precision ground gauges that ONLY work on those features. GO/NOs are ideally used in high volume applications where you need to check something fast. Personally I think needing to know whether your carrier is .001" +/- is OVERKILL (I think he said the differences between the carrier rods was that amount). Your hair is .004" thick. Anodizing can be .005" thick. HELL, TOUCHING THE PART CAN CHANGE THE BOLT CARRIER .001" JUST FROM BODY HEAT. Thats why metrology labs are completely climate controlled. Are those gauge pins spec'ed for the temperature he's working at? Unless you are in a climate controlled room and NOT TOUCHING THE PART; your measurement could be different tomorrow at those scales. But if you must, most machinist supply companies sell gauges (i.e. McMaster); you just need to know the target diameter you need. Just google x.xxx" bore gauge. If you really wanted a large range of pins for the entire AR, just get a inexpensive Chinese gauge pin sets (with a .0002" tolerance) on Amazon that has dozens of pins through a size range.
I like this video as your others. It seems to me you need a 25 to 50 line questioner for those who send you their uppers and BCG's as to possibly get bottom of some of the wear or corrosion you find. This might teach others what to or not to use or do as possible prevention of in future. Just a thought.
What is the purpose of dimpling the cam pin/reinstalling in the same orientation every time? I can't imagine it affects accuracy, and if it was put back together in the other direction half the time wouldn't that even out the wear?
If someone had a nitride bcg and a phosphate bcg, and they weighed exactly the same. Why would the nitride one take less gas to run than the phosphate one when using an adjustable gas block?
BCM exact words= NOTE: We use a lot of MI Reaction Rods here in our shop, however we almost always remove the upper wing. The tolerance stacking of the vertical wing can make it incompatible with some milspec upper receivers.
Good day. I have a question and may be you can help finding an answer. I have windham 308, pretty nice gun. But it had a problem in the bolt. There is a port in carrier with pin to lock the bolt. The problem was - during manufacturing bolt port was milled to deep, making walls on the bottom too thin, as a result, during usage small part of bolt were chipped of, scratched insides of the carrier. I was thinking bolt is not reliable as it had chips of metal already - who knows maybe it could can in two in most crucial moment. So I requested replacement, and Windham was ready to replace it, which I am pretty glad about, and need to admit they treasure their reputation. Unfortunately the only problem who i had to face - was local distributor, it seems they do not care. Nevertheless i got it replaced and all seems fine now. Can you please shed the light on the situation? I wonder if i was right or overcautious. To state the direct question - are chips of metal from the bolt on the bottom of locking pin port any danger to bolt and can be a symptom of future bolt brake? Thank you.
Chad, I have a question for you but I really don't expect an answer for obvious liability reasons but here goes. After watching your vid on the PSA autopsy which I really learned a lot from because I was contemplating buying an AR pistol from them it got me thinking. What is your opinion of RIA firearms? I presently own an LAR 8 & a AR15, chromed bolt carrier group and elite operators edition. They do cost a bundle and because I live out of the country and only return to the US infrequently I doubt if I've put 100 rounds through each, all NATO ball. Thank you.
Showing that they're tight enough to seal and prevent blow by which I believe could lead to the chamber opening before it should which could lead to a ruptured case. Also, it probably could lead to cycling problems. If you sort by his most popular videos he shows a cut away of a bcg and shows what those rings do. I haven't seen him fail one that way in the number of vids I've watched, but the rings, tail and inside of the BCG all have to be within spec.
so was wondering at 22:47 that wasnt tooling marks? a previous video led me to this video with that exact thing and if thats the case, dude got a used bolt carrier from primary arms
I love this channel and I’ve learned so so much already. I do have an important tech question. The rubber O-ring on the extractor spring, should I install one if not equipped from the factory? And if I swap the spring to an upgraded one, should it have the O-ring installed?
From what I have seen on Chad’s videos, BCM, SOLGW, and Geissele have been on the very consistent in the spec realm. But I understand no one manufacturer is perfect. Microbest I believe makes the BCG’s for SOLGW and BCM. The co-owner of SOLGW Mike Mihalski actually talks about it in one of the origin videos about how he called Microbest everyday for a month when they first started.
Question: At minute 11:00 you show both extractors side by side, the one on the right, the spring retainer looks bent, is that camera angle or is it bent? It appears bent through out the whole portion you discuss the springs and donut issue. Thank you.
I have the same bcm bcg as you but my ejector insert sleeve doesn’t look like yours. Your sleeve looks to be the full length of the spring and mines looks to only be halfway. Is that because you’ve swapped out to the Sprinco or is mines damaged. Got 600rds no malfunction but the cam key is pretty beat up.
Hello there! I enjoy your content allot... learn about this platform from your video's. End up here just few days I just got my first AR15, a Sig Sauer M400, with 16 inch barrel. Shoot it just few times... just enough to adjust my red dot (mount a Romeo 5) When I study the empty shels I discover a dent, about at the three quarters from the back of the cartridge. On a study at the fotage, frame by frame, I discover that the dent is done when the empty shel is ejected and it hits the shell deflector. Is this means the gun is over gassed?... to much pressure? I should do something to protect the gun not to distroy himself? Something that is not required anz special tools... I'm fare from the tool set you are equiped... 🙂 Thank you in advance for your help.
Sounds pretty overgassed. A lot of companies do that so you can run just about anything reliably, but it puts extra wear on your barrel and bcg over time. Not a huge concern as it's very common but not great.
If the bolt Carrier gets into the Red gauge on the gas ring run, will it still pass the gas ring support test when standing upright on the bolt? Thank you for the informative videos.
Look at the headspace gauges. They are not typical gauges. Typical headspace gauges require the ejector and extractor to be removed for the AR. My gauges are relieved to clear the extractor and ejector.
@@2wheeleddemon999 The ion bonded bcg finish is a penetrating treatment. It's not like nickel boron or some other finish. It is "bonded" to the metal and does penetrate the surface. As he said it could be a wear or corrosion issue. However this has led me to the decision to just stick with BCMs standard bcg's from now on. Only if to save a few bucks.
The five coil is very aggressive and rips the brass out of there. For reliability. Sprinco recommends the four coil if you reload and reuse your brass.
For guys wondering why SOTAR won't give recommendations on BCG or barrel manufacturers, you're missing the point, which is that inspection-verification of individual components is more important than where the components came from. Yes, maybe certain manufacturers are more consistent, but no manufacturer is 100% perfect.
Thank you John
I think people would like to know who the more consistent manufacturers are.
It's similar to an auto mechanic who knows which cars are more reliable, on average, and people asking so that they can have a higher chance of buying a more reliable car.
Yeah, but that's more $ in precision gauges then it would be to build 2 AR's. If "the point is to inspect the dimensions" it would seem better to use only calipers when possible or at least having the gauge diameters marked.
Otherwise he is giving advice without giving advice, when he says "this BCM is an anomaly" makes me proud I went BCM.
@Justin if you watch enough of his videos, you will pick up on what manufacturers are "generally" in spec. If you read between the lines you will find the information you are searching for.
@@5jjt BCM, LMT, Toolcraft, Bootleg, KAC(proprietary though), these are some good ones. I personally run BCM BCGs and several uppers and I love them. They make a quality product at an affordable price. I think they produce a better rifle than Daniel Defense which is more expensive.
IF you get a BCM lower(most BCMs I see are an Aero lower using a BCM upper, or some other brand of lower) you'll get a polished nickel coated trigger(so enhanced milspec essentially), a rifle that tends to be pretty well gassed, a good rail(though to be fair this is one area where DD might be superior) and a good barrel. DD just gives you a regular milspec trigger and their rifles are very commonly SERIOUSLY overgassed. I think they've gotten better about it more recently but they're still over gassed. I have a block 2 m4 upper from DD and its overgassed whereas I have a BCM 14.5(Both the DD block 2 m4 and BCM are pinned and welded) with midlength gas system and it was perfectly gassed right out of the box with military grade 5.56 using just a normal carbine weight buffer.
I can't get enough of these videos. I have a whole 3 day weekend coming up that I plan on catching up on all the ones I've missed.
Apparently YT unsubbed me because I've missed 2+ months of vids that I'm binging at work.....
Watched about 5 minutes of this video and immediately subscribed. That knowledge of bolt stretching and cam pin issues is something that I may never have learned about in my life. Thanks for passing your knowledge on to people who want to learn.
I quickly learned after I found this channel I was suffering from a little bit of the "Dunning-Kruger" effect when it came to my knowledge on the AR platform. I believed that I knew a lot more than I actually did. He's doing people who really want to learn a great service and I would jump at a chance to learn from him in person. Just a great channel and a great resource, I've really learned a lot from him
4⁴4
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As you were inspecting these two BCG's, a thought went through my mind. As popular of your channel has become, I would bet that you could sell bolt carriers with the SOTAR insignia etched onto them. I know it would interest me. Think about it, and try to find someone to do it for you. you have the business, designed a logo, you have merchandise, this would be one more thing to bring in income.
I’ve been waiting for a BCM bcg physical and it looks like BCM’s quality control (at least for the phosphate bcg) is fantastic as usual. I did have to send an upper back to them last week, it’s a MK2 BFH 11.5” that would not pass a 5.56 go gauge. After 1.5 days it was on its way back to me. I also have a MK2 BFH 14.5” pinned and welded and it passed perfectly fine. Thanks again for the awesome video. Still the best content on RUclips!!!
@ARcoholic ARcoholic Its an extra level of piece of mind if you're getting a brand new receiver for either a complete upper or a build I would say. Its friendlier for using an ambi charging handle for sure, cause the FA is moved a bit forward. That being said, if you already have a normal conventional upper receiver, dont feel as if you need to replace all of them with BCM Mk2s.
I’ve been wanting a 14.5” bcm middy for years now! Wonder if the mk2 is worth the upgrade 🧐
As the owner of two MK2’s and several mil spec BCM’s, I’ll take the MK2 over the mil spec any day. Where they relocated the shell deflector and forward assist, it gives you a lot more room to run offset iron sights. Also, in comparison it’s substantially more robust in critical areas and I find it visually more appealing than a normal upper. Just my two cents, hope it helps.
Parker Allison I want one so bad!! I just hope that when I get it, it’s good to go and doesn’t have any QC issues since I’ve heard some folks have had problems with their uppers due to the insane demand as of lately.
Love my BCM 14.5 mid. I got the enhanced light weight barrel and it just feels so wieldy. I was worried my groups would open up severely after long strings of fire but really they don't. Not enough to matter anyway.
These vids are addicting. I swear I think I am a certified armorer in 1 year. Being a veteran mechanic helps
First video ive ever seen from this page and immediately subscribed.
Hey, new subscriber here! Would you be willing to make a video discussing what your standard modifications or changes to a BCG are and why you perform them? It'd be interesting to see your reasoning, as a newbie to this more involved aspect of firearms.
Zen and the art of the American Rifle
So maybe stick with the standard BCM bcg's. I actually have two of the ion bonded bcg's and I trust them almost exclusively. I've baught from Spikes, Noveske, Aero, and PSA for some of my builds an I usually find something off with all but the BCMs.
Although after watching many of your videos on bcg's I've come to some new conclusions about stuff. For example I don't get ood coatings like nickel boron anymore. I also look for more tolerance issues beyond just the gas ring seal now to. Additionally I replace yfs fasiners almost immediately.
So long story short your information is very helpful thank you.
I've seen 2 bad bcgs from bcm. One gas key broke loose at about 1200 rounds. 2nd was out of spec bolt itself. Ejector not moving freely inside bolt body. Bcm is just like everyone else, and have issues occasionally
@@Helibeaver Sure everyone has issues I get that. However what I meant was it's probably best to just save money and buy the regular bcg's instead of the ones with the fancy coatings. Possibly more chance the regular finishes are in spec since it's something that's been a known quantity for years.
I have a WMD NiBx BCG with around 1300rnds in an SBR and I have no coating issues. From what I've seen, not all coating/bondings are created equal, just like any BCG, barrel etc.
are the ion bonded chrome lined inside?
Chad- I’ve noticed your subscriber count skyrocket bud. Congrats on the success from a fellow Maryland shooters member :)
He deserves it for all the knowledge and awesome
Tips he gives to the community! Things like checking your bolt catch spring with the weight of the bolt or if you’re field stripping your bcg you can put all of the parts and fit them all inside the groove on the charging handle. Those are only some of many tips you will gain from watching him work. It’s top tier stuff and I love it!
The take away from this video is I don't really know much about BCGs
Having been a fan of the ar platform for many years, it is just since I found your channel that I can get the info needed to truly troubleshoot issues and figure out the root problems to troublesome guns. However finding a lot of the go, no go gauges you have is impossible.
Love it, love everything about your channel. I've learned extensively and appreciate each video. Thank ya sir!
Let’s be real. Some of the bolts are built by the same manufacture. Who knows unless you do your research. So each video gives a small look into the manufacturer. Medals. Ect. So much like a engine. How the medals mate. How they wear. I can’t get enough of these videos.
I like Centurion's Chrome Sandcutter Carrier and their dual ejector bolt. I saw SOTAR's examination of said carrier and that honestly just reinforced what I was already thinking.
Just found this channel over the past weekend. Great content and thank you for sharing. Just watched the UNISSUED U.S.G.I. M16/A1/A2 ARMORERS TOOL KIT video tonight, pretty cool stuff you are doing.
Another amazing video!
Are there any blueprint books with dimensions and tolerances on these AR 15/ AR 10 components?
I would love to own own a few of these. Any recommendations?
Both of my FN ARs, a 16" M4 and an 18" match grade sporter use both the extractor spring and (brown) insert. Theyve always ran flawlessly but i also added a blue O-ring.
I have almost 16k rounds on the M4 and 13k rounds through the sporter without issue.
Im actually amazed by both rifles. Not only are they consistently sub MOA accurate and 100% reliable but theyre both as durable as the proverbial hammer it seems.
The barrels have lost perhaps 1/8" to 1/4" of accuracy at 100 yds though still can pull 5) rd groups of 1/2" when i do my part with their preferred loads.
The BCGs look like brand new still. Just the slightest finish wear on the ends of the carrier rails. Ditto for the bolts. The finish wear on the lug faces are very slight and perfectly even. The extractors have a polished look at the leading edge of the case bevel but otherwise look new. Piston rings are still holding just like new and while clean and lubed and with the piston rings dead center of the gas ports, easily support the weight of the carrier + a standard aluminum Okay Surefeed G.I. magazine loaded with 3 to 4 green tip rounds (a field expedient method i use to determine BCG health)
The cam pin still has 95% of its finish and fits snug with minimal play. I have noticed theres a bit more play side to side than front to back which is practically nill.
And that brings me to my first of a few questions. If bolt stretch is the mechanism that generally causes the demise of a bolt (as far as cam pin/bolt tail is concerned), wouldnt the cam pin hole show more play in the front to back or axial direction (in line with firing pin) rather than side to side or laterally?
Obviously i dont have all the gauges and tools to properly check wear but the fact that i can definitely detect more play in one direction over the other, is that a viable method to determine the health of the bolt and if not what does this finding suggest if anything?
And finally, just how long should i expect these things to run and should i go ahead and replace anything as a precaution?
Ive always heard a good chrome lined barrel will last 10k to 15k, a good bolt should be replaced at 5k as per Eugene Stoners suggestion.
Im well beyond that and running just fine. What gives and what if anything should i replace?
Thanks in advance for your reply if you do!
Love your videos man! Teaching me a lot of shit I never thought of considering
Have you done any tests on Aero Precision products? I built one so i would like to know what t o expect.
Chad do u have a top 5 suggested bcgs? I've never heard you mention your suggested bcg or barrel manufacturers. Would really appreciate your input with several options
Awesome question 👍🏻I would also like2 know
Yeah In very curious too.
Check out his physical of the Geissele
He doesn't give recommendations
He owns 1 of the BCM BCG. that should tell you something
Maybe someone used a corrosive agent like CLR to attempt cleaning before you got the BCG from them. Something like that would etch it like that.
Did you check head space of his bolt and his barrel that had the feed ramp issue? I'm sure you did but was wondering what the outcome was.
Yes. It's was good. Good question though.
I would like to hear your thoughts on building an ar15 in 762x39 maybe instagram be a better place to have this convo thanks 🙏 great vids
@School of the American Rifle You have a lot of gauges that are clearly hard to come by. Do you have a list or reference somewhere that lists the dimensional tolerances for each of the checks you're performing? I recognize you don't need them if you have the gauges, but for a guy like me who has gauge pins, micrometers, etc. it would be helpful to have a list of tolerances. Thanks
Chad, I have two rifles built with that specific BCG from BCM and that is a nitride coated BCG and I have seen the same thing on mine. Also, you might want to mention why you put that mark on the roller pin. As I recall from your class, you said that roller pin should always be installed the same way, thus the mark.
Coated Bravo BCG pitting is most likely incompatible materials which results in "Galvanic" or "Dissimilar Metal" corrosion.
Sometimes lubricants that contain chlorinated esters cause corrosion and pitting issues too.
Keep up the good work. I've learned so much just by watching your videos. They are also relaxing for some odd reason.
Do you make your own tools/gauges or is there a place that sells them? Great vids
I would love to hear about that as well.
I would also like to have a few of the ones you have, for my own checking. Specifically the bcg ones
I believe hes said in certain videos a lot of them he sells only to people who take his class, some are custom made for him and some you can buy from retailers
Chad, the demand for gas efficient bolt carrier groups inspected and verified by you would sell like hot cakes.
Totally! Assuming you can pay him to review your stuff or that only in classes?
Either way, just do what SOLGW does and buy microbest BCGs then pay Chad to upgrade spring and inspect haha...
(For the record they do apparently individual HPT & MPI their bolts)
Very curious about this one as bcm claims they 100% check every bolt including gauging boat tail, gas ring and shoulder etc … happy to see one brown down to this degree as they are considered and I believe want to be quality through and through as lives depend on their product
Can you do some more reviews, and what is the name of your business? Thanks. Excellent technical content best I've seen.
I always purchase plain ole Colt phosphate bcg's no coating to wear off and the Colts have never let me down.
If they never let you down why do you keep having to purchase them, a collector I presume; makes me wonder about longevity, what's your highest round count?
BCM bcg's best on the market. I really like my Recce 16
2nd best, IMO. SOLGW is #1 to me.
Where do you get most of your tools and gauges, it would be good to know,...
Yeah, i need those too.
Love all your videos, such a wealth of knowledge! Where did you purchase all these different gauges from??
Where can you find some of these gauges?
Outstanding demonstration on a bcg.
You should check gas key alignment when gas tube is installed. There are no moving parts through the gas tube opening in the upper reciever. I understand why you do check it with gas tube out because machining could be off on upper.
Amazing videos. Tons of knowledge, through and no weird ramblings. Now to check out all my stuff😂
I would love to see a physical on sons of liberty gun works BCG.
Just found your videos were have you been my whole life lol. Maybe You have made a video on this topic. I just purchased a custom barrel by dead shot barrels in terrabon Oregon, great people good turn around, he cut my bolt to my barrel. What's your take on that? And is that an actual good functioning thing to have happen? Like your awesome opinion. I'm a engineer for 30 years and I knew there was a guy like you out there thats No bolt Carrier are alike and with all your jigs and tolerances. I knew that there were a lot of factors into one. Keep up the good work man. Thanks.
I've become kind of addicted to these videos. I've been putting together AR's for years, but I've never known the proper way to inspect the different parts. Thanks for making these.
I do have one question, what is the significance of the parts having magnetism?
I've been wondering about that and can't find any info on the innertube.....lol
I’ve heard him say so you don’t get any small pieces around the firing pin that could cause it to fail
The reasoning behind the magnetism tests is for when you're shooting steel cased ammunition, as shavings can accumulate over time on the parts that do have magnetism and can cause issues in higher round counts
Great content!! I had a bolt that had 2 of the lugs sheer clean off while firing. What would cause this?
I’ve asked many people but now I’ve found the wizard!
What causes the bolt to be magnetized, and how do you demagnetize the bolt?
Heat
(Long answer has to do with increased movement of electrons abd their tendency to "line up" their "spin")
I'm sure harbor freight has a de-magnatizer (it's some substance that you rub the metal on, the composition of which is an excellent question for an inorganic chemist, I'm more organic (love me some nmr's and reaction mechanisms))
That fde is worth its weight in gold right now.
Sometimes more expensive, is more expensive.
I wonder if some foreign ammo have corrosive primers?
What is the most consistent BCG manufacturer?
Great video, I learned a lot about maintaining my bcg. I have a carbon tool with firing pin cleaning hole and set of calipers. I just purchased a go/ no go gage set. In your opinion what would your next bcg tool to add? I can’t afford to purchase everything in your video all at once. Thanks for any input your willing to share.
My bcm bcg bolt came with the o ring on the spring plus another o ring in a bag for short barrel rifles. Should I remove the o ring if im just running a 16inch?
Hey their, you said you recommend tapco extractor spring, good place to order it from?
And what would be a good camera for a normal everyday guy , only use it from time to time, and good place to buy one from, Thanks alot!
Is there a place to purchase those gauges?
Love your vids! Can you please provide a vid on proper lubrication? Im always wondering how much oil I should be using in the trigger mech and such. Thanks!
so if you grab some go juice, just a drop on each contact surface of the trigger
Could you please get together a set of all the gauges that I would need to check a diamondback 300blkout, please? I have looked and am coming up empty-handed. I'll pay whatever it costs I'm asking you because I trust you completely after watching your videos!!!
I'll hopefully be starting gunsmithing in the fall/winter and I can put the gauges to good use I have a micrometer that is analog but I think I may get a digital version at some point
Why is it important to check for magnetism, and how do parts become magnetized in manufacturing?
Im no expert, but i think he said in a previous video that if you use steel ammo sometimes small steel shavings from the ammo will stick to the magnetized parts and cause premature wear.
Parts can become magnetized in different machinery during manufacturing. Like if a mill vise or lathe chuck is magnetized, anything it holds could become magnetized.
@E-Tron it's actually someone not demagnetizing after MPI that's the issue.
@@ScottKenny1978 Correct
@E-Tron Correct
Where could I get a set of the gauges you use? I would love to be able to check my bolts, uppers and barrels with them
Telescoping gauges and a caliper will get you most the dimensions unless its really small. It's overkill for a normal person to use all those bore gauges. You could easily spend hundreds getting precision ground gauges that ONLY work on those features. GO/NOs are ideally used in high volume applications where you need to check something fast.
Personally I think needing to know whether your carrier is .001" +/- is OVERKILL (I think he said the differences between the carrier rods was that amount). Your hair is .004" thick. Anodizing can be .005" thick. HELL, TOUCHING THE PART CAN CHANGE THE BOLT CARRIER .001" JUST FROM BODY HEAT. Thats why metrology labs are completely climate controlled. Are those gauge pins spec'ed for the temperature he's working at? Unless you are in a climate controlled room and NOT TOUCHING THE PART; your measurement could be different tomorrow at those scales.
But if you must, most machinist supply companies sell gauges (i.e. McMaster); you just need to know the target diameter you need. Just google x.xxx" bore gauge. If you really wanted a large range of pins for the entire AR, just get a inexpensive Chinese gauge pin sets (with a .0002" tolerance) on Amazon that has dozens of pins through a size range.
Great video! What lubes do you recommend? Also would you recommend using grease instead of lube on the high contact portions of the bolt and carrier ?
He recommends a mixture of oil and grease mixed to a consistency of liquid dish soap.
Where does one get some of these gauges?
Good morning y'all
I like this video as your others. It seems to me you need a 25 to 50 line questioner for those who send you their uppers and BCG's as to possibly get bottom of some of the wear or corrosion you find. This might teach others what to or not to use or do as possible prevention of in future. Just a thought.
Are nicks in the rail a concern? I’ve bought a few BCM BCGs in the past year or so and they all have had a few nicks on the guide rails.
Please don’t disable comments! We don’t expect you to respond if it’s not feasible, we completely understand
I bet gun shops hate you. Ah yea can I take a look at that rifle sir? (pulls out laptop the bore cam and all his guages)
What is the purpose of dimpling the cam pin/reinstalling in the same orientation every time? I can't imagine it affects accuracy, and if it was put back together in the other direction half the time wouldn't that even out the wear?
He explains that in another video. Reversing it actually causes it to wear out faster.
If someone had a nitride bcg and a phosphate bcg, and they weighed exactly the same. Why would the nitride one take less gas to run than the phosphate one when using an adjustable gas block?
BCM upper receivers are clocked. MI Reaction Rod won’t engage. Reached out to BCM , they said this is normal ?
Not acceptable for something I work on.
BCM exact words= NOTE: We use a lot of MI Reaction Rods here in our shop, however we almost always remove the upper wing. The tolerance stacking of the vertical wing can make it incompatible with some milspec upper receivers.
Good day. I have a question and may be you can help finding an answer. I have windham 308, pretty nice gun. But it had a problem in the bolt. There is a port in carrier with pin to lock the bolt. The problem was - during manufacturing bolt port was milled to deep, making walls on the bottom too thin, as a result, during usage small part of bolt were chipped of, scratched insides of the carrier. I was thinking bolt is not reliable as it had chips of metal already - who knows maybe it could can in two in most crucial moment. So I requested replacement, and Windham was ready to replace it, which I am pretty glad about, and need to admit they treasure their reputation. Unfortunately the only problem who i had to face - was local distributor, it seems they do not care. Nevertheless i got it replaced and all seems fine now. Can you please shed the light on the situation? I wonder if i was right or overcautious. To state the direct question - are chips of metal from the bolt on the bottom of locking pin port any danger to bolt and can be a symptom of future bolt brake? Thank you.
Chad, I have a question for you but I really don't expect an answer for obvious liability reasons but here goes.
After watching your vid on the PSA autopsy which I really learned a lot from because I was contemplating buying an AR pistol from them it got me thinking.
What is your opinion of RIA firearms? I presently own an LAR 8 & a AR15, chromed bolt carrier group and elite operators edition. They do cost a bundle and because I live out of the country and only return to the US infrequently I doubt if I've put 100 rounds through each, all NATO ball.
Thank you.
I have seen splaching with corrsive ammo.
Idk why but sometimes your voice reminds me of Jeff Goldblum.
Explain the gas ring test.
I know what they are and their function.
What is the upside down standing gonna show?
Showing that they're tight enough to seal and prevent blow by which I believe could lead to the chamber opening before it should which could lead to a ruptured case.
Also, it probably could lead to cycling problems.
If you sort by his most popular videos he shows a cut away of a bcg and shows what those rings do.
I haven't seen him fail one that way in the number of vids I've watched, but the rings, tail and inside of the BCG all have to be within spec.
@@JamieR2077 Thank you
Bcm makes the best direct gas impingement ars by far. Plus they don’t sell to Fudd states and gov agencies.
Thank you for another lesson.
What does dimpling the cam pin do for you? I’ve not seen that before and I’m just curious.
12:57
Andy Adventuring I definitely missed that part when I watched it the first time!
Allows you to easily verify you're reinstalling the cam pin in the same orientation each time to maintain a consistent wear pattern.
so was wondering at 22:47 that wasnt tooling marks? a previous video led me to this video with that exact thing and if thats the case, dude got a used bolt carrier from primary arms
I love this channel and I’ve learned so so much already. I do have an important tech question. The rubber O-ring on the extractor spring, should I install one if not equipped from the factory? And if I swap the spring to an upgraded one, should it have the O-ring installed?
He's said a few times don't do both.
There's a spring co kit for $5 that comes with the o ring he says leave it out
@@JamieR2077 yep already did it. Springco 5 coil did the trick
I have a new BCM BCG, and if I were to re-install the cam pin the same way it was test fired, would the worn side face forward or aft?
Was the customer one the ionbond bcg that BCM advertises?
From what I have seen on Chad’s videos, BCM, SOLGW, and Geissele have been on the very consistent in the spec realm. But I understand no one manufacturer is perfect. Microbest I believe makes the BCG’s for SOLGW and BCM. The co-owner of SOLGW Mike Mihalski actually talks about it in one of the origin videos about how he called Microbest everyday for a month when they first started.
Question: At minute 11:00 you show both extractors side by side, the one on the right, the spring retainer looks bent, is that camera angle or is it bent? It appears bent through out the whole portion you discuss the springs and donut issue. Thank you.
I have the same bcm bcg as you but my ejector insert sleeve doesn’t look like yours. Your sleeve looks to be the full length of the spring and mines looks to only be halfway. Is that because you’ve swapped out to the Sprinco or is mines damaged. Got 600rds no malfunction but the cam key is pretty beat up.
What's the purpose behind the dimpling?
Hello there! I enjoy your content allot... learn about this platform from your video's. End up here just few days I just got my first AR15, a Sig Sauer M400, with 16 inch barrel.
Shoot it just few times... just enough to adjust my red dot (mount a Romeo 5)
When I study the empty shels I discover a dent, about at the three quarters from the back of the cartridge.
On a study at the fotage, frame by frame, I discover that the dent is done when the empty shel is ejected and it hits the shell deflector.
Is this means the gun is over gassed?... to much pressure? I should do something to protect the gun not to distroy himself?
Something that is not required anz special tools... I'm fare from the tool set you are equiped... 🙂
Thank you in advance for your help.
Sounds pretty overgassed. A lot of companies do that so you can run just about anything reliably, but it puts extra wear on your barrel and bcg over time. Not a huge concern as it's very common but not great.
If the bolt Carrier gets into the Red gauge on the gas ring run, will it still pass the gas ring support test when standing upright on the bolt? Thank you for the informative videos.
Yes. It just won't seal as well and the gas rings get eaten faster.
Did you run steel cased ammo through it without cleaning the carrier for a week or two OR more
So the ejector doesn’t need to be removed to check headspace. Thanks.
Look at the headspace gauges. They are not typical gauges.
Typical headspace gauges require the ejector and extractor to be removed for the AR.
My gauges are relieved to clear the extractor and ejector.
@@SchooloftheAmericanRifle thank you sir
So much for that FDE Ion Bond finish. I wonder if the owner was using the carrier on a 5.45x39 AR upper at one time.
That's why I will always go for treated metal over a finish.
@@2wheeleddemon999 The ion bonded bcg finish is a penetrating treatment. It's not like nickel boron or some other finish. It is "bonded" to the metal and does penetrate the surface. As he said it could be a wear or corrosion issue. However this has led me to the decision to just stick with BCMs standard bcg's from now on. Only if to save a few bucks.
@ARcoholic ARcoholic Lack of proper maintenance does not mean the part is of poor quality!
What he doesn't tell you. After the inspection he knows your SS number, mothers maiden name and pin numbers.
What extractor spring from springco do you recommend a 4 or 5 coil, why and what’s the difference please? Thank you.
The five coil is very aggressive and rips the brass out of there. For reliability. Sprinco recommends the four coil if you reload and reuse your brass.
Do you recommend running the cam pin in the same direction every time??
I've always wondered why he did this as well. He explains it at the 12:22 mark
How often do you offer your classes?
what does the dimple on the cam pin do?
If I run into a bcg with a extractor spring insert and a doughnut, is it worth removing one or the other ?
Could it be the owner of the other bcg is using corrosive ammo??
I have a fairly new (has a couple hundred maybe rounds) PSA BCG. Can I send to you for a physical? Stakes look a bit weak.
Any experience with the new cmc enhanced bcg?
Where can I purchase the swabs that you use ?
What kind of lub/protection do you recommend?