I've learned more about the AR platform from SotAR than in my 24-year military life dealing with Small Arms. The explanation of the gas function as it pushes the bolt forward has completely changed my visualization of the firing sequence. Thank you and glad to see Rebel again.
Despite having learned a good bit about the mechanics and intricacies of the AR (a good bit from your videos) I was still able to learn a new thing about the pressurization in the BCG taking load off of the bolt lugs, thus prolonging their service life. The content you put out is simply astonishing and the internet and RUclips don't deserve you.
A friend of mine has a cool cutaway. It's a 5.56 barrel that fired a 300bk. The bullet looks to be about 2 inches long and about 3 inches down the bore.
OK on top of everything else, you’ve got the best wife a man could want! I more or less understood what was happening inside the BCG, but seeing the cutaway is a fantastic teaching tool. Seeing the actual parts works best for my brain. Thanks! ETA: there is so much good information here that I miss things the first time through. In this case, it was your comments about the firing pin retaining pin possibly indicating a poor gas seal for the bolt tail or excessive BCG speed.
this guy is awesome.. I did 20+ yrs in the infantry, and I think this small but clear period of instruction would have been very beneficial as a constant carrier of this weapon system. It would make a better shooter and caretaker of the weapon. ensuring the shooter understand the type and quality of required maintenance needed to keep the firearm in good firing condition. great class!! wow!
God this video is SO cool! I LOVE all this nerdy stuff about the AR, I absolutely love the process of when, where, and why you test! Please don't ever stop this train Mr. A! All the testing and info you provide for the community, might I add for (FREE) here on RUclips is invaluable! Thanks for all you sir! Merry Christmas to you and the family, and may 2022 bring the Biggest and BEST year for SOTAR yet 🤘
This is absolutely the best video I’ve ever seen on the Mechanics and Theory of AR operation.. those little bits of gold like a beat up bolt retainer pin = tail shaft leakage.. amazing. This video should mandatory in Basic Training for all military branches. I know they aren’t Armorers but they know the how and why. Thank You brother for such amazing content!
I thought I understood everything about the operating cycle till I watched this video. Sharing such great educational information with the public makes you a true patriot.
Great instruction. In the army we were told the gas pushed the the bolt carrier back. Did not even know that gas was getting inside the carrier and pushed on the bolt. I finally understand why there are rings on the bolt. Stoner did a great job designing this system!
So glad you mentioned the gas rings lining up. I remember learning that in boot camp and always thought that was a necessary check. Also didn't know the gas rings compressed as they're put in the BCG
Amazing content. The firearm cutaway is what happens when skill, understanding & passion meet: a work of art. Seriously. Thanks for your dedication to sharing your knowledge. May you continue for as long as you wish. Liked how Rebel answered when spoken to. 😎
This is an INCREDIBLE video. Your wife hit a home run with that Valentine's Day gift. No amount of cartoons or animation will show as clearly how the bolt and bolt carrier interact during firing as you did with the actual metal parts. Now I know exactly why the bolt tail is always caked with carbon, and I also know that I probably need to do a better job cleaning the inside "chamber" of my BCG that is hidden so it's "out of sight, out of mind". Thank you for this.
Really interesting to watch this deep dive into the AR system. It further exemplifies how polar opposite the design ethos was between the M16 weapon system and the AK47.
I’ve always appreciated the talent and skill of the mechanically inclined. But what makes SOTAR truly remarkable, is your ability to simplify and share these lessons with others. Thanks.
I had a good idea of the BCG's operation inside the weapon and that cutaway along with your explanation confirmed it! thanks Chad... good to see Rebel again too 👍
This is even more clear than those cut away graphics videos showing all the intricacies. It's kind of like photography and football. You can learn a lot by just watching videos like that but you really have to have someone who understands the thing well to explain it properly.
This was a great breakdown. I'm a super nerd for technical information about things I enjoy - cars, computers, guns, etc. You are a great teacher, and these are some fantastic teaching props!
So after watching this detailed demonstration, I learned something that I never thought about. Which is, the gas pushing/making forward pressure on the gas rings and bolt. You say that it removes some of the load from the lugs but wouldn’t this also help with the unlocking? The gas is pushing the carrier rewards but since the gas chamber is also pushing on the back of the gas rings creating forward pressure on the bolt, this should also help the cam rotation! Very useful video. Goes to show you how useful the D.I. System is. Whenever someone makes a comment about its faults, if they only knew how everything is working together they’re actually beneficial to the operation.
I'm watching this long after the fact but thank you for the visual and explanation. This is a truly ingenious design, not a pure DI and not a pure piston, but a combination of both that works extremely well. It would be very interesting to hear Stoner's thought process when he was designing this.
Interesting to hear about increased bolt wear with a gas piston AR. I've had two and I don't think that they solve ANY problem on an AR and introduce more of them.
I don't own one and I don't want one but I belive the point is to assist suppressed shooters by moving the gas out of the receiver. Suppressors make the receiver far dirtier far faster.
@@pythonBlender7 actually, that was the only advantage to my Sig 516. It had an adjustable gas system which did improve the function with a suppressor, but my CMMG aftermarket GP adapter did not.
@@pythonBlender7 Most of the extra fouling from shooting suppressed is coming back out of the barrel and into the action, so piston ARs still get a lot dirtier than non suppressed shooting. Just like how suppressed AKs get filthy. Only way to avoid extra fouling with a can is some sort of delay unlock that let's the suppressor depressurize before unlocking, which would require either some rube Goldberg system or manual operation. Piston ARs were mostly invented for two reasons. Misconceptions and people who believe all the crock about AR15s being unreliable, and the military wanting shorter and shorter barrels and manufacturers not switching gas tube lengths leading to short barrel AR15s with absolutely no dwell time that were barely able to cycle regularly.
Apart from suppressed use they are more reliable in dirty conditions. Such as overseas in a desert environment. They do come with more recoil, but less cleaning. More wear and tear too. Many pros and cons to each system.
@T800 incorrect they were developed for better reliability and survivability when using full auto or extended time of constant use in semi auto. They also do not noticeably build up carbon deposits when using a can. By the time the bullet is traveling through the can the piston rod has already smacked the bcg and put it in motion so you see the usual places when suppressing your AR.
I am SO glad I found SOTAR. Thank you for providing this well presented information. I have learned more about the AR DI platform in the last week from watching your videos than in last 32 years of owning one. 👍🏼🇺🇸
After watching this nobody with basic mechanical understanding should be calling the AR a direct impingement weapon anymore. In Eugene Stoner's words it is an internal piston system and I wholeheartedly agree.
I'm one of those guys that learns by seeing it all first hand. Seeing you take the time to do some educating like this brings me joy my dude. Thank you.
What a great vid! I have been troubleshooting a bolt related problem and stumbled on your explanation. You have expanded my understanding and it's greatly appreciated!!!
When I was learning, I had so much trouble figuring out why the rifle wouldn't cycle. I LOVE videos like this, they help me understand the mechanics of what's happening so I could better diagnose the issues. Thank you!
No apologies for the interruption needed. After all, his name is Rebel. Been a sub for... idk, a couple years. I love learning & gaining better understanding. You can't get this level of information anywhere but here. Thank you for doing what you do and doing it so well! You know you have serious students when there are zero dislikes!
I learned a lot about the particulars of each component within the BCG and how darn complex these things are. I also appreciate your recognition that tolerances on different parts can be matched in a complementary fashion to yield a well-functioning gas system.
Marvelous explanation of the gas functionality of the venerable AR joystick! I built one from scratch a while back. The cutaway vastly helped me to see/understand how she really works. A thousand thanks for putting this together .
I was KP the day they explained a lot of this stuff. I had to ask other guys a lot of questions. I survived. Brings back memories keeping this bolt clean, or else.
Very cool thank you for sharing this! I love cutaway’s, not only are they just plain cool but I also find it a bit easier to understand operation through a cutaway vs something like a 3D diagram.
Thank you! I'm one of the visual types. When trying to follow discussions (arguments??) about 'internal piston or DI', I had trouble visualizing how the BCG actually functioned as a piston. This video really helped.
I was just looking for vids on BCG when I came across this video. This video was such a good visual learning experience. Thank you so much for this way of teaching, with cutaways, efficiency gauges, etc. I wish more vids could be like this.
Absolutely the best video I’ve seen on the gas system. When piston conversions for ARs first became a thing, and were all the rage on fanboy websites, I tried to explain the disadvantages I saw, including increased bolt lug wear, but was shouted down by the mobs. BTW, you’re a great teacher as well as being extremely knowledgeable.
The guy who got me into shooting at the range always insisted AR-15s are horrible because they throw gas into your action and i couldnt believe it was that stupid because so many people (and militaries) use it. This video properly showcased the reason, the up and downsides and the inner workings of the AR action. truly, a very nice video and a great piece of teaching equipment.
This was an awesome video! I understand so much more than I did before about the operation of the rifle. Now I know why some areas are so dirty when it's cleaning time. Loved seeing Rebel too.
Im a Quality Analyst at an engine factory, though my passion is guns. I love studying this stuff, how things can go wrong and how they are supposed to work. This is really similar to a steam engine in a way, except it's powder gas driving the piston instead of steam, lol. Or even a two-stroke engine, since the piston still acts as it's own exhaust valve.
Of all my time working on AR's I never made the connection that the same pressure that pushes back on the carrier also pushes forward, relieving some stress on the lugs... Best educational channel on RUclips. Hands down.
Respectfully, the load the bolt cares about from a fatigue life standpoint is the load at peak pressure. By the time the bullet passes the bleed orfice in the barrel, the chamber pressure has dropped to 1/3 or 1/4 of peak, meaning the pressure forward on the bolt is a fraction of it’s peak value. Bleeding gas into the bolt carrier reduces the contact load between the bolt lugs & the lock extension lugs, making it easier to unlock the bolt.
This is the most informative vid ive ever seen on the BCG. I just recently replaced my rings on my 10.5 with a fixed 5" brake. Was having issues and when i disassembled it, the forward most ring was broken in 2 pieces. I got curious before reassembly and put one down with 2 rings. It worked. Great teaching good sir. Im subd.👍
When I was at school for the airlines, I could read something 20 times and kind of get it. But whenever they took us into the aircraft and showed us things that’s when I really got it. Definitely a visual learner.
Another one of your incredible videos. I will definitely be sharing with anyone I know new to the AR. 👍🏻 I wish your videos were around in 2007. I could’ve saved myself a lot of time. Thank you for taking the time to share all of this info with us.
I really need to remember what you said. I wished I was watching this while I have my ar open up for cleaning/oiling. I liked your parts. Your video just popped up. I am going to subscribe. I love your cat.
I've been looking for a video that uses AR-15 cutaways for ages...finally found yours. What a great job of explanation, too. The visual of the cutaways with your explanation makes all the difference. I didn't realize that there was a purpose for the forward pressure applied to the bolt at the start of the cycle (unloading the lugs). The rest I knew but couldn't really visualize until seeing the cutaways. Your explanation of what you've found in these guns and what could go wrong is very educational as well. Also, your troubleshooting gauges are well thought out and easily understood. The cutaway of the gun itself is great, but the cutaway of the bolt carrier showing how the bolt and gas key fit into it and how bolt and bolt carrier move together is priceless.
This is an outstanding video. Thank you for taking the time to teach us with the cut aways. I was a unit armorer when I was in the Army 40 some years ago and I am always learning 😊 All the best, Norm in Arizona
I just happened to stumble upon this channel and I’m SO glad I did. I love all this technical stuff and it helps to understand our rifle platform better. I wish I could get a set of all those gauges and check out my own rifles, but I don’t know if they’re available, and I’m guessing they wouldn’t be economical to someone who only owns a few rifles and doesn’t do this for a living, even if they are. Please keep making your videos, because they are fascinating, and even without your specialized tools, you’ve taught us that there are a lot of things an owner can inspect and watch out for in our own rifles. Thank you.
Awesome, detailed explanation. Rebel looks like an awesome kitteh too. I keep delving deeper into your catalog of info. Thank you for making the world a little more intelligent with every day. I like to learn at least one new thing a day and you help me with my goal. Appreciate you folks. 🤙🏾
Absolutely FANTASTIC video!!! Been goofing around with and building these things for 30 years and like many others commented already, I’ve learned more in the 20min of their video than 30 years of tinkering and reading! 👍👍
Brownells used to carry a one piece gas ring set. I haven't seen them in some time. I used to use them all the time and gas ring wear was not as much of an issue as it could get on hard run guns. Loved this cut away vid, it visualized perfectly how I understood the process to work. Great for those that are new to the DI Ar15 system!
Watched a many of your bcg physicals. I knew you were checking for efficiency but I didn’t understand how before now. Probably the single biggest learning moment of my gun owning life. Thank you for the content.
The number one ability of a good teacher is the fact he can explain things to the reciever. You definitely meet that mark with this one. Plus you have a very romantic wife with Valentines gift like that.
This hit precisely in the neighborhood of the problems I am seeing in my first Build. I opted for the original ARStoner Firing Pin Retaining Pin over the cotter pin in a (not named) BC with its matched Bolt (6.5/6ARC). There is a lot here, but we will get to it below, and its demise. The experienced young man who got me involved with the AR system told me I gummed up the action with a Corrosion X bath, making a thick coating, chamber, action, everything. It did not originally cycle. Turned out it was the SI Adjustable Collar Gas Block that had to go. SI stated that their product was not designed for the 6.5G, nor the 300AAC (more on that below), so I went to Kaw Valley AGB wide open. Also used something like mineral spirits to break up the coating of the Chamber and internals. Then it was not ejecting. By the time the BCG was tested again, it was tried out in a 6.5G PL 10.5", it was DF-FEx, and SP, almost every round on Test #1. (Yes, a more extensive set of problems.) Post Test Examination found that the original Stoner style FPRP was broken. It bent one of the clip end legs off. (Everything you had talked on here.) Back to the Cotter Pin. Bought extras. Light lubed everything with CLP. Now sporting the KV AGB, wide open to prove operability, particles are showering back at the operator as with Test #1. After 3 rounds today, the Cotter Pin (staying with that as cheap and operational is far better) is not appearing to be bent nor stressed. What we saw was Stove Piping and Failure to Eject. So. This vid has shown me all of the forces that I am up against, and beginning the day, I had already known by tests that I could move the extractor on the bolt with a metal shafted tool, unlike a 300AAC BCG Extractor recently acquired which I could not move.(Boy oh boy did that NiBo BCG run smooth. I would like to say something about running that upper, but I cannot recall anything about it as it was so uneventful--SI AGB working on that Caliber- Hard to believe I shot anything at all) First step was change out the obvious Ext Spring assembly, and used the BCM Brand product with the O-ring. Far more rigid under pressure, and the spring is about 50% longer than what came on the factory (not named) BCG. If this fixes it, I am fine. Not bad for about $72. I have learned that Ext Springs are the cheat part on lower end BCGs. Seems that the legend of running an Extractor without a spring is precisely that; mere legend. I never thought that this Armalite action was simple like the AKs that I am used to. The trap of the AR caught me with the Multi Caliber options. This video to me seemed like a week long course. Excellent explanations and exposure of every point of stress and energy. If I detect any bend in that FPRP after this new Extractor Spring improves the reliable function that we can bring the Gas down, I now know what it is, and it is the deepest part of the Gas Expansion Chamber of the BCG. Whether it is the Bolt extension or the Extension Passage I am not going to be able to detect as you can with those excellent gauges. It will go back to the factory, with the original Extractor Spring. I will then be extremely tempted to get a Ni-Brn BCG for the 6.5/6ARC. I have some reason to not believe that I merely got lucky with that selection. Mr. Stoner and Mr. Sullivan did some excellent work in light of that hidden place. The fact of how it allows the Bolt Carrier to begin rearward travel while holding the Bolt still in the path of travel, taking all pressure off the Bolt Lugs and Barrel Ext Lugs as the bolt rotates, is stellar thought. Far far far different Tech than the brutality of the AK (not that such is bad) but this explains everything as to how those locking lugs are each .5 to .33 of an AK lug and not being sheered off. I can understand why traditionally trained owners would overclean that location, and especially if they got a hold of corrosive or semi-corrosive ammo. At this point you, and the young guy working with me on this AR project, have convinced me to go with light lube on this system, and not to be OCD about keeping the expansion chamber spotless. The 6.5 today was running on the CLP, and it got some Molybdenum on sliding and bearing surfaces. Still issues as noted above. The 300AAC was running on a product recommended to me by an Armorer (Retired Lt. Cmdr. Hambridge) for 3 NC SWAT Teams who worked on ARs, but preferred my Galil in 308 to them. It is Ballistoil. Next we will see if it operates at the 2nd Gas Aperture above shut off on the SI Collar Adj Gas Block. Thank you for your work on Mr. Stoner and Mr. Sullivan's designs. You are very thorough.
Sir, I appreciate the detailed description on the gas and how it works... The years it took to get the intuitive knowledge of that specific device astounds me.. I applaud you... Job well done.!!
Excellent video. I knew most of this but there were a few things in this video that i did not know and i now have a better understanding of the gas system thanks.
You Sir are THE Go-Too Instructor for this particular rifle platform, if anyone wanted to take such into the professional repair/commercially oriented build spheres youre classroom courses is def the place to do so... -Happy New Year to y'allz...;)
Yes this is very cool and I think good to understand. The cut outs really show functionality and makes me realize how smart the people were that came up with the AR platform. To not only come up with the concept but to get everything designed and timed just right for it to work perfectly is mind blowing. Too bad your classes are not closer to the West Coast. Great job on the channel.
I don't own an AR. I love bolt actions. However, If I ever did buy one your video taught me a couple of things and the most important one is don't go cheap when buying one!
I've learned more about the AR platform from SotAR than in my 24-year military life dealing with Small Arms. The explanation of the gas function as it pushes the bolt forward has completely changed my visualization of the firing sequence. Thank you and glad to see Rebel again.
If only I could have seen this 35 years ago, I would have actually understood why it functions. Thanks!
are you Ashli babbitt?
All these videos are priceless
Worrying that a soldier didn't understand guns.
This is a cool video but I don't know how you would not know and understand all this with a 24 year military career dealing with small arms lol
I've built probably 20 ARs from various parts and kits but every time I click one of your videos I still find myself extremely humbled.
As a visual learner/understander…this is fantastic. Thank You!
Found it educational and just plain cool. Those cutaway's are awesome.
Absolutely a genius design. The sort of thing you see in a dream after decades of obsessive passion over a subject.
Despite having learned a good bit about the mechanics and intricacies of the AR (a good bit from your videos) I was still able to learn a new thing about the pressurization in the BCG taking load off of the bolt lugs, thus prolonging their service life. The content you put out is simply astonishing and the internet and RUclips don't deserve you.
That was new to me also. This is the best on the web.
A friend of mine has a cool cutaway.
It's a 5.56 barrel that fired a 300bk.
The bullet looks to be about 2 inches long and about 3 inches down the bore.
THAT would be incredible to see. I cant imagine how catastrophic that discharge was. Hope everyone survived without injury.
I want to see that! Do you have a picture?
Holy cow, hope the person whose shoulder was back there is okay!
I'd love to see the cutaway...
OK on top of everything else, you’ve got the best wife a man could want!
I more or less understood what was happening inside the BCG, but seeing the cutaway is a fantastic teaching tool. Seeing the actual parts works best for my brain. Thanks!
ETA: there is so much good information here that I miss things the first time through. In this case, it was your comments about the firing pin retaining pin possibly indicating a poor gas seal for the bolt tail or excessive BCG speed.
this guy is awesome.. I did 20+ yrs in the infantry, and I think this small but clear period of instruction would have been very beneficial as a constant carrier of this weapon system. It would make a better shooter and caretaker of the weapon. ensuring the shooter understand the type and quality of required maintenance needed to keep the firearm in good firing condition. great class!! wow!
God this video is SO cool! I LOVE all this nerdy stuff about the AR, I absolutely love the process of when, where, and why you test! Please don't ever stop this train Mr. A! All the testing and info you provide for the community, might I add for (FREE) here on RUclips is invaluable! Thanks for all you sir! Merry Christmas to you and the family, and may 2022 bring the Biggest and BEST year for SOTAR yet 🤘
This is absolutely the best video I’ve ever seen on the Mechanics and Theory of AR operation.. those little bits of gold like a beat up bolt retainer pin = tail shaft leakage.. amazing. This video should mandatory in Basic Training for all military branches. I know they aren’t Armorers but they know the how and why. Thank You brother for such amazing content!
Great video with very clear views and valuable information. And the guest appearance of Rebel was a nice surprise.
Semper Fidelis 🇺🇸
The first demo of the carrier was great....
The cut out rifle was even better....
The Annology was one of the best I have seen.
Outstanding!
GREAT VIDEOS FROM THIS SCHOOL...!!!!!!!
I thought I understood everything about the operating cycle till I watched this video. Sharing such great educational information with the public makes you a true patriot.
Great instruction. In the army we were told the gas pushed the the bolt carrier back. Did not even know that gas was getting inside the carrier and pushed on the bolt. I finally understand why there are rings on the bolt.
Stoner did a great job designing this system!
I freakin nerd out on these videos, please don't stop teaching. Can't thank you enough for all that you do.
So glad you mentioned the gas rings lining up. I remember learning that in boot camp and always thought that was a necessary check. Also didn't know the gas rings compressed as they're put in the BCG
Amazing content. The firearm cutaway is what happens when skill, understanding & passion meet: a work of art. Seriously.
Thanks for your dedication to sharing your knowledge. May you continue for as long as you wish. Liked how Rebel answered when spoken to. 😎
Some people think with words, some of us think in pictures. This sort of thing is extremely helpful to me for understanding how things work.
This is an INCREDIBLE video. Your wife hit a home run with that Valentine's Day gift. No amount of cartoons or animation will show as clearly how the bolt and bolt carrier interact during firing as you did with the actual metal parts. Now I know exactly why the bolt tail is always caked with carbon, and I also know that I probably need to do a better job cleaning the inside "chamber" of my BCG that is hidden so it's "out of sight, out of mind". Thank you for this.
Really interesting to watch this deep dive into the AR system. It further exemplifies how polar opposite the design ethos was between the M16 weapon system and the AK47.
Awesome cutaways. I've occasionally had trouble explaining to people in the past that the AR is more complicated than "gas makes carrier go back."
This is the most important channel for anyone who owns an AR-15
I’ve always appreciated the talent and skill of the mechanically inclined. But what makes SOTAR truly remarkable, is your ability to simplify and share these lessons with others. Thanks.
I had a good idea of the BCG's operation inside the weapon and that cutaway along with your explanation confirmed it! thanks Chad... good to see Rebel again too 👍
This is a GREAT video and shares more knowledge in 20 mins then most ever! Thank you so much for all you do!!
Fantastic video. I really appreciated seeing how the gas traveling behind the bolt starts the process of unlocking it!
What makes these videos valuable is everyone can learn what to do but few know the REAL why and you get that here.
Very enlightening. Just as fascinating is a guy who's wife gets him a bolt cut away for valentine's day. I love it.
This is even more clear than those cut away graphics videos showing all the intricacies. It's kind of like photography and football. You can learn a lot by just watching videos like that but you really have to have someone who understands the thing well to explain it properly.
This was a great breakdown. I'm a super nerd for technical information about things I enjoy - cars, computers, guns, etc. You are a great teacher, and these are some fantastic teaching props!
So after watching this detailed demonstration, I learned something that I never thought about. Which is, the gas pushing/making forward pressure on the gas rings and bolt. You say that it removes some of the load from the lugs but wouldn’t this also help with the unlocking? The gas is pushing the carrier rewards but since the gas chamber is also pushing on the back of the gas rings creating forward pressure on the bolt, this should also help the cam rotation! Very useful video. Goes to show you how useful the D.I. System is. Whenever someone makes a comment about its faults, if they only knew how everything is working together they’re actually beneficial to the operation.
I'm watching this long after the fact but thank you for the visual and explanation. This is a truly ingenious design, not a pure DI and not a pure piston, but a combination of both that works extremely well. It would be very interesting to hear Stoner's thought process when he was designing this.
Thank you. Awesome demonstration
Finally! The only video I can find that has a real BCG cutaway! Thank you!
I’ve been saving this until I was done compiling. This video is my relaxation for the week. Thank you
Thanks for such a clear explanation. I'm no gun smith, but I love knowing about exactly how my machines work.
Interesting to hear about increased bolt wear with a gas piston AR. I've had two and I don't think that they solve ANY problem on an AR and introduce more of them.
I don't own one and I don't want one but I belive the point is to assist suppressed shooters by moving the gas out of the receiver. Suppressors make the receiver far dirtier far faster.
@@pythonBlender7 actually, that was the only advantage to my Sig 516. It had an adjustable gas system which did improve the function with a suppressor, but my CMMG aftermarket GP adapter did not.
@@pythonBlender7 Most of the extra fouling from shooting suppressed is coming back out of the barrel and into the action, so piston ARs still get a lot dirtier than non suppressed shooting. Just like how suppressed AKs get filthy. Only way to avoid extra fouling with a can is some sort of delay unlock that let's the suppressor depressurize before unlocking, which would require either some rube Goldberg system or manual operation.
Piston ARs were mostly invented for two reasons. Misconceptions and people who believe all the crock about AR15s being unreliable, and the military wanting shorter and shorter barrels and manufacturers not switching gas tube lengths leading to short barrel AR15s with absolutely no dwell time that were barely able to cycle regularly.
Apart from suppressed use they are more reliable in dirty conditions. Such as overseas in a desert environment. They do come with more recoil, but less cleaning. More wear and tear too. Many pros and cons to each system.
@T800 incorrect they were developed for better reliability and survivability when using full auto or extended time of constant use in semi auto.
They also do not noticeably build up carbon deposits when using a can. By the time the bullet is traveling through the can the piston rod has already smacked the bcg and put it in motion so you see the usual places when suppressing your AR.
Very educational, thank you! And yes EDM is amazing on how precisely the cuts are.
The cutaway with the gages was fantastic! Connects the dots on what’s happening, also shows value in your gages, nicely done!
I am SO glad I found SOTAR. Thank you for providing this well presented information. I have learned more about the AR DI platform in the last week from watching your videos than in last 32 years of owning one. 👍🏼🇺🇸
After watching this nobody with basic mechanical understanding should be calling the AR a direct impingement weapon anymore. In Eugene Stoner's words it is an internal piston system and I wholeheartedly agree.
What an incredibly well designed system.
I'm one of those guys that learns by seeing it all first hand. Seeing you take the time to do some educating like this brings me joy my dude. Thank you.
What a great vid! I have been troubleshooting a bolt related problem and stumbled on your explanation. You have expanded my understanding and it's greatly appreciated!!!
When I was learning, I had so much trouble figuring out why the rifle wouldn't cycle. I LOVE videos like this, they help me understand the mechanics of what's happening so I could better diagnose the issues. Thank you!
No apologies for the interruption needed. After all, his name is Rebel. Been a sub for... idk, a couple years. I love learning & gaining better understanding. You can't get this level of information anywhere but here. Thank you for doing what you do and doing it so well! You know you have serious students when there are zero dislikes!
I learned a lot about the particulars of each component within the BCG and how darn complex these things are. I also appreciate your recognition that tolerances on different parts can be matched in a complementary fashion to yield a well-functioning gas system.
Marvelous explanation of the gas functionality of the venerable AR joystick!
I built one from scratch a while back. The cutaway vastly helped me to see/understand how she really works.
A thousand thanks for putting this together .
I was KP the day they explained a lot of this stuff. I had to ask other guys a lot of questions. I survived. Brings back memories keeping this bolt clean, or else.
Very cool thank you for sharing this! I love cutaway’s, not only are they just plain cool but I also find it a bit easier to understand operation through a cutaway vs something like a 3D diagram.
Thank you! I'm one of the visual types. When trying to follow discussions (arguments??) about 'internal piston or DI', I had trouble visualizing how the BCG actually functioned as a piston. This video really helped.
Best demonstration about firearms functioning I've seen hands down
Because of this video we diagnosed a problem, fixed it.
Now the works good with all ammo!
Amazing video, thanks for sharing your knowledge
I was just looking for vids on BCG when I came across this video. This video was such a good visual learning experience. Thank you so much for this way of teaching, with cutaways, efficiency gauges, etc. I wish more vids could be like this.
Thanks for making this video, this is a great way to explain the full operation of the system. Also very cool to see cut-aways!
Absolutely the best video I’ve seen on the gas system. When piston conversions for ARs first became a thing, and were all the rage on fanboy websites, I tried to explain the disadvantages I saw, including increased bolt lug wear, but was shouted down by the mobs.
BTW, you’re a great teacher as well as being extremely knowledgeable.
The guy who got me into shooting at the range always insisted AR-15s are horrible because they throw gas into your action and i couldnt believe it was that stupid because so many people (and militaries) use it. This video properly showcased the reason, the up and downsides and the inner workings of the AR action. truly, a very nice video and a great piece of teaching equipment.
This was an awesome video! I understand so much more than I did before about the operation of the rifle. Now I know why some areas are so dirty when it's cleaning time. Loved seeing Rebel too.
Im a Quality Analyst at an engine factory, though my passion is guns. I love studying this stuff, how things can go wrong and how they are supposed to work. This is really similar to a steam engine in a way, except it's powder gas driving the piston instead of steam, lol. Or even a two-stroke engine, since the piston still acts as it's own exhaust valve.
Of all my time working on AR's I never made the connection that the same pressure that pushes back on the carrier also pushes forward, relieving some stress on the lugs...
Best educational channel on RUclips. Hands down.
I agree. "Learn something new each day" my dad would say, and I did. Great Video!
All bcg parts are extremely complicated to be machined.
Are they originally casted in production?
Or how were they made?
RebelCat! Yay!
This was an awesome demonstration! Thank you for sharing. :)
Man this channel is such a great resource. You guys are incredible. Awesome job 💯
Respectfully, the load the bolt cares about from a fatigue life standpoint is the load at peak pressure. By the time the bullet passes the bleed orfice in the barrel, the chamber pressure has dropped to 1/3 or 1/4 of peak, meaning the pressure forward on the bolt is a fraction of it’s peak value. Bleeding gas into the bolt carrier reduces the contact load between the bolt lugs & the lock extension lugs, making it easier to unlock the bolt.
This is the most informative vid ive ever seen on the BCG. I just recently replaced my rings on my 10.5 with a fixed 5" brake. Was having issues and when i disassembled it, the forward most ring was broken in 2 pieces. I got curious before reassembly and put one down with 2 rings. It worked. Great teaching good sir. Im subd.👍
Magnificent training tool. Thank you for taking the time to show this and explain.
When I was at school for the airlines, I could read something 20 times and kind of get it. But whenever they took us into the aircraft and showed us things that’s when I really got it. Definitely a visual learner.
I send this video to all my military friends. So they can see the operation of their weapon. Thanks. Perfect for some people
That bolt carrier cutaway is *awesome!*
I didn't grok how the AR _actually_ worked at all till I saw that.
Another one of your incredible videos. I will definitely be sharing with anyone I know new to the AR. 👍🏻
I wish your videos were around in 2007. I could’ve saved myself a lot of time. Thank you for taking the time to share all of this info with us.
Really cool to see a physical demonstration and explanation of why piston systems are not > than DI ones. Awesome video, thanks for sharing
I really need to remember what you said. I wished I was watching this while I have my ar open up for cleaning/oiling. I liked your parts. Your video just popped up. I am going to subscribe. I love your cat.
I've been looking for a video that uses AR-15 cutaways for ages...finally found yours. What a great job of explanation, too. The visual of the cutaways with your explanation makes all the difference. I didn't realize that there was a purpose for the forward pressure applied to the bolt at the start of the cycle (unloading the lugs). The rest I knew but couldn't really visualize until seeing the cutaways. Your explanation of what you've found in these guns and what could go wrong is very educational as well. Also, your troubleshooting gauges are well thought out and easily understood. The cutaway of the gun itself is great, but the cutaway of the bolt carrier showing how the bolt and gas key fit into it and how bolt and bolt carrier move together is priceless.
Love the hanging out and learning aspect of this video.
This is an outstanding video. Thank you for taking the time to teach us with the cut aways. I was a unit armorer when I was in the Army 40 some years ago and I am always learning 😊
All the best,
Norm in Arizona
Your video reaffirmed what my minds eye saw. Thank you much.
Very very interesting, I finally understood how the AR system works, many thanks for the clear and precise explanation.
Great Viedo. I always learn so much watching how you analyze analyze the various systems.
The cutaway is awesome.
Thanks 😊
I haven’t watched a video one of yours that hasn’t blown my mind in comparison to what I thought I knew about AR’s.
Love it!
As a new AR armorer your videos are incredibly valuable. I appreciate all the work that you do to help me learn in addition to my training.
I just happened to stumble upon this channel and I’m SO glad I did. I love all this technical stuff and it helps to understand our rifle platform better. I wish I could get a set of all those gauges and check out my own rifles, but I don’t know if they’re available, and I’m guessing they wouldn’t be economical to someone who only owns a few rifles and doesn’t do this for a living, even if they are. Please keep making your videos, because they are fascinating, and even without your specialized tools, you’ve taught us that there are a lot of things an owner can inspect and watch out for in our own rifles. Thank you.
Awesome, detailed explanation. Rebel looks like an awesome kitteh too. I keep delving deeper into your catalog of info. Thank you for making the world a little more intelligent with every day. I like to learn at least one new thing a day and you help me with my goal. Appreciate you folks. 🤙🏾
What an excellent cutaway! I'm sure that's a fantastic resource to show to students :)
I feel like this RUclips channel saved me thousands of dollars by taking the AR class from SDI. Thank you for your service on here.
Absolutely FANTASTIC video!!! Been goofing around with and building these things for 30 years and like many others commented already, I’ve learned more in the 20min of their video than 30 years of tinkering and reading! 👍👍
Very educational. I'm a picture type of guy that grasps ideas and concepts better with visual rather than books. Thanks.
Brownells used to carry a one piece gas ring set. I haven't seen them in some time. I used to use them all the time and gas ring wear was not as much of an issue as it could get on hard run guns. Loved this cut away vid, it visualized perfectly how I understood the process to work. Great for those that are new to the DI Ar15 system!
Watched a many of your bcg physicals. I knew you were checking for efficiency but I didn’t understand how before now. Probably the single biggest learning moment of my gun owning life. Thank you for the content.
Really love this channel. I'm a huge fan of DI stoner system. Thanks for sharing
The number one ability of a good teacher is the fact he can explain things to the reciever.
You definitely meet that mark with this one.
Plus you have a very romantic wife with Valentines gift like that.
Fairly New AR owner here & this is a VERY INFORMATIVE video.... Thanks for sharing
This hit precisely in the neighborhood of the problems I am seeing in my first Build. I opted for the original ARStoner Firing Pin Retaining Pin over the cotter pin in a (not named) BC with its matched Bolt (6.5/6ARC). There is a lot here, but we will get to it below, and its demise.
The experienced young man who got me involved with the AR system told me I gummed up the action with a Corrosion X bath, making a thick coating, chamber, action, everything. It did not originally cycle. Turned out it was the SI Adjustable Collar Gas Block that had to go. SI stated that their product was not designed for the 6.5G, nor the 300AAC (more on that below), so I went to Kaw Valley AGB wide open. Also used something like mineral spirits to break up the coating of the Chamber and internals.
Then it was not ejecting.
By the time the BCG was tested again, it was tried out in a 6.5G PL 10.5", it was DF-FEx, and SP, almost every round on Test #1. (Yes, a more extensive set of problems.)
Post Test Examination found that the original Stoner style FPRP was broken. It bent one of the clip end legs off. (Everything you had talked on here.)
Back to the Cotter Pin. Bought extras. Light lubed everything with CLP.
Now sporting the KV AGB, wide open to prove operability, particles are showering back at the operator as with Test #1. After 3 rounds today, the Cotter Pin (staying with that as cheap and operational is far better) is not appearing to be bent nor stressed.
What we saw was Stove Piping and Failure to Eject.
So. This vid has shown me all of the forces that I am up against, and beginning the day, I had already known by tests that I could move the extractor on the bolt with a metal shafted tool, unlike a 300AAC BCG Extractor recently acquired which I could not move.(Boy oh boy did that NiBo BCG run smooth. I would like to say something about running that upper, but I cannot recall anything about it as it was so uneventful--SI AGB working on that Caliber- Hard to believe I shot anything at all)
First step was change out the obvious Ext Spring assembly, and used the BCM Brand product with the O-ring.
Far more rigid under pressure, and the spring is about 50% longer than what came on the factory (not named) BCG. If this fixes it, I am fine. Not bad for about $72. I have learned that Ext Springs are the cheat part on lower end BCGs. Seems that the legend of running an Extractor without a spring is precisely that; mere legend.
I never thought that this Armalite action was simple like the AKs that I am used to. The trap of the AR caught me with the Multi Caliber options. This video to me seemed like a week long course. Excellent explanations and exposure of every point of stress and energy.
If I detect any bend in that FPRP after this new Extractor Spring improves the reliable function that we can bring the Gas down, I now know what it is, and it is the deepest part of the Gas Expansion Chamber of the BCG. Whether it is the Bolt extension or the Extension Passage I am not going to be able to detect as you can with those excellent gauges. It will go back to the factory, with the original Extractor Spring. I will then be extremely tempted to get a Ni-Brn BCG for the 6.5/6ARC. I have some reason to not believe that I merely got lucky with that selection.
Mr. Stoner and Mr. Sullivan did some excellent work in light of that hidden place. The fact of how it allows the Bolt Carrier to begin rearward travel while holding the Bolt still in the path of travel, taking all pressure off the Bolt Lugs and Barrel Ext Lugs as the bolt rotates, is stellar thought.
Far far far different Tech than the brutality of the AK (not that such is bad) but this explains everything as to how those locking lugs are each .5 to .33 of an AK lug and not being sheered off.
I can understand why traditionally trained owners would overclean that location, and especially if they got a hold of corrosive or semi-corrosive ammo.
At this point you, and the young guy working with me on this AR project, have convinced me to go with light lube on this system, and not to be OCD about keeping the expansion chamber spotless.
The 6.5 today was running on the CLP, and it got some Molybdenum on sliding and bearing surfaces. Still issues as noted above.
The 300AAC was running on a product recommended to me by an Armorer (Retired Lt. Cmdr. Hambridge) for 3 NC SWAT Teams who worked on ARs, but preferred my Galil in 308 to them. It is Ballistoil. Next we will see if it operates at the 2nd Gas Aperture above shut off on the SI Collar Adj Gas Block.
Thank you for your work on Mr. Stoner and Mr. Sullivan's designs. You are very thorough.
Sir, I appreciate the detailed description on the gas and how it works... The years it took to get the intuitive knowledge of that specific device astounds me.. I applaud you... Job well done.!!
Excellent video. I knew most of this but there were a few things in this video that i did not know and i now have a better understanding of the gas system thanks.
You Sir are THE Go-Too Instructor for this particular rifle platform, if anyone wanted to take such into the professional repair/commercially oriented build spheres youre classroom courses is def the place to do so...
-Happy New Year to y'allz...;)
Yes this is very cool and I think good to understand. The cut outs really show functionality and makes me realize how smart the people were that came up with the AR platform. To not only come up with the concept but to get everything designed and timed just right for it to work perfectly is mind blowing. Too bad your classes are not closer to the West Coast. Great job on the channel.
I don't own an AR. I love bolt actions. However, If I ever did buy one your video taught me a couple of things and the most important one is don't go cheap when buying one!
Bravo, la meilleure méthode pour comprendre le fonctionnement d'une arme automatique. Merci.
Your wife got you an EDM cutaway BCG for Valentines day..... That is a keeper right there.
I have learned more about bolt carrier function in your video than I would have ever suspected. Excellent presentation. Thank you.