Two things I have learned watching this channel. This is the second time I've seen Knights bolt carrier's with loose fitment issues. The Giessllie Superduty bolt carrier past these very same test with an added comment about Giessllies results being good enough tobe used in competition. The Superduty could be the new top tier AR bolt carrier on the civilian market until someone creates something better. 🇺🇲✝️🇺🇲✝️🇺🇲
Agreed 100%. Especially considering they adhere to TDP spec and non-proprietary parts. During a livestream of their new products a few years back, I jokingly asked Bill about the wood table he had everything displayed on. It triggered his extreme attention to detail OCD, and he starting rambling about the type of wood, how it was made, blah blah blah. The point is, he knows details, and that is what makes their products so successful. I have only run LMT E-bcgs for a while, but I had one of these civilian Sandcutter carriers, and was not impressed with the QC. I'll be switching everything to the G REBCG's now, especially considering their price and availability.
First thing I always check when someone has an AR that's not cycling correctly with good ammo is the gas key. 9/10 times it's either the fasteners aren't torqued or staked correctly, or one or both are broken. ESPECIALLY on a low round count rifle. Nice video :)
Thanks Chad! I would really like to see a video on extracting a broken fastener. If the owner wants the broken BCQ back, could you please show us another example?
@@onpsxmemberif it was me and I was paying $500+ for a BCG/$2,000 for an upper receiver, $4,000 for a complete rifle, they can stick their sample sizes up their ass. It better be right. If it's not, what the hell are you paying for ?
the e3 bolt will only work in the sr15 uppers, which have different chambers cut for the knurled lugs on the e3 bolt face. this is not an e3 bolt and bcg, but a normal one meant for non-sr15 uppers.
You have defiantly motivated me to become a gunsmith! I start at SDI for their associate's degree in firearms technologies! I know I will get some hate for this but I have some GI bill left and want to sue it for this degree. I have been unable to find a mentor close to me so this is my only option. This might help me get my foot in the door.
This is an incredibly educational channel!! I would love be able to do this for a living. I’ve always heard when you do something you love for a living that is not work. If I could do this then I’d never work a day again in my life.
Great video sir I really wish I could come join you at one of your classes but unfortunately no money for plain flight ✈️ & plus the number one I Reason no money for your class but please keep making the videos very interesting lots of great info
It's not as big of a deal if it's not the most efficient, especially because a crazy large number of AR's on the market are grossly overgassed so it actually kinda helps. But for a well gassed AR I think I remember him doing a couple new BCM's that passed with flying colors, one of which was his own. There are others but aren't coming to mind. Also as you use them they will obviously wear and those tolerances will get bigger as time goes on, but as long as your gas key is done right and there's no real leaks it should run fine if there's no other real problems
Forward control designs BCG have always done amazingly as well. Watched this entire catalog of bolt carrier group testing and FCD has had extremely tight tolerances. Building my first AR-15 and still deciding between LMT enhanced bcg and Scionics/FCD.
there are always going to be mistakes made, but it is interesting to see a KAC bolt carrier messed up like that i agree. I'd still trust a carrier from KAC but this is something to keep an eye out for now that we see at least one instance of this happening.
People should keep in mind that most individual firearm parts are inspected on the AQL system. Brands that commands a higher price will inspect a higher percentage of parts, but most parts will still be sent through without inspection if the batch passes QC so some bad parts can slip through.
Could you do one on miss alignment of upper to lower receivers? such as chatter marks on the bottom of a BCG, really curious because I have sent back an AR 9mm for this three times.
This is why I stopped buying KAC stuff. I started noticing tolerances and QC started to slip, a lot. For the price premium, it's just not worth it. The E3 bolt is interesting, but the proprietary everything just doesn't make sense to me.
I imagine you see all kind of issues with ARs I have a problem. I have a barrel that has a muzzle brake pined and welded. And I want to remove the brake and have it redone. It wasn't done right. What is the safest way to remove it so I don't damage the barrel.
Chad, please forgive my ignorance. What is the deal with magnetism check on the firing pin and bolt? What would cause a bolt or FP to become magnetic? What problems would it cause?
If parts are magnetic and you shoot steel cased ammo, it possible that casing and projectile shavings can stick to operating surfaces. This can cause reliability issues.
I would get all three: go, no-go, and field. The go needs to fit in, if it doesn't stop using that rifle NOW. If the Field fits, stop using that rifle, NOW. No-go is the maximum as-new size, it safe to shoot even if the no-go chambers. Each one tells you something different. If you only have the no-go, you won't know if the chamber is too tight or too loose. Not to mention that I don't think you can buy them individually.
Chad, maybe as part of your BCG autopsies, you could run compressed air thru the gas key opening, while the bolt is in, and check for leaks around the gas key w/ some mixture of soap & water?
Doesn’t newer KAC rifles have the rounded bolt lugs? My older KAC does and I thought that was a feature they were proud of. The bolt here doesn’t have rounded lugs.
I dont think thats an SR-25 bolt. I own an SR25 ECC and my bolt is chrome like the rest of the carrier. The lugs are also rounded (as well as other stuff). I believe the owner of that gun is running a different bolt on that carrier. As far as I know, KAC is particular about parts from other companies being compatible with their stuff.
Field gauge is the final step before being unsafe. This is because if something fails the field gauge it is unsafe to use in any case, even in life or death situations such as in the "field". But if it passes a field gauge while failing a no-go then the item can be used but it will not be optimal. no-go is more for the purpose of ensuring a quality product while field gauge tests the safety of a product.
Or maybe they appreciate the "heads up" on their QA/QC process. Any mfr that cares about quality would appreciate learning about something that slipped through the cracks.
Reggie Kanan and? It was clearly stated in the video. KAC sand cutters are sold as a bolt carrier without bolt, allowing you to use the bolt of choice in non KAC barrels due to barrel extension and bolt being proprietary to knights.
The amount of knowledge gained on this channel is insane
Seriously dude!! Great stuff.
Two things I have learned watching this channel. This is the second time I've seen Knights bolt carrier's with loose fitment issues. The Giessllie Superduty bolt carrier past these very same test with an added comment about Giessllies results being good enough tobe used in competition. The Superduty could be the new top tier AR bolt carrier on the civilian market until someone creates something better. 🇺🇲✝️🇺🇲✝️🇺🇲
Agreed 100%. Especially considering they adhere to TDP spec and non-proprietary parts. During a livestream of their new products a few years back, I jokingly asked Bill about the wood table he had everything displayed on. It triggered his extreme attention to detail OCD, and he starting rambling about the type of wood, how it was made, blah blah blah. The point is, he knows details, and that is what makes their products so successful. I have only run LMT E-bcgs for a while, but I had one of these civilian Sandcutter carriers, and was not impressed with the QC. I'll be switching everything to the G REBCG's now, especially considering their price and availability.
Every single second of this video was a learning experience for me, and I've built several AR's. Phenomenal job diagnosing the failure. Subscribed.
First thing I always check when someone has an AR that's not cycling correctly with good ammo is the gas key. 9/10 times it's either the fasteners aren't torqued or staked correctly, or one or both are broken. ESPECIALLY on a low round count rifle.
Nice video :)
This video blew my mind. Thank you for the information!
You just increased my knowledge of understanding the AR platform thanks abunch. Great video
Such an underrated channel. Keep pumping out these technical videos
i learned more in the last 15 minutes that i did from 4 years in college. outstanding sir.
I've definitely got some amazing tips from this channel on how to double-check ARs and troubleshoot issues I have.
This dude is a weaponry MD .I learned so much from him. He should have way more Subscribers then he does my hat is off to you sir.
I found your channel from a Facebook post. I am very happy I did.
Great video Chad, thanks for the great content
Holy ish- MUCH respect..., m’captivated with your knowledge- & will follow closely for sure! Thx thx thx!
Thanks Chad! I would really like to see a video on extracting a broken fastener. If the owner wants the broken BCQ back, could you please show us another example?
I can watch these videos all day ! Love your content man ! Thanks for all the knowledge too lol
KAC has there own proprietary bolt. I wonder if the BCG works better with kAC’s bolt and has different tolerances
You rock, thank you so much for sharing your knowledge!!
Can't wait to take your course!
From knights armament I'd expect perfection, especially with the cost of their products.
Sometimes you are just paying for the name
@@jaredbickmore2474
Sample size of one.
@@onpsxmemberif it was me and I was paying $500+ for a BCG/$2,000 for an upper receiver, $4,000 for a complete rifle, they can stick their sample sizes up their ass. It better be right. If it's not, what the hell are you paying for ?
For almost $500 ($1000+ if you get the SR25 bolt carrier and E2 bolt.) for the bolt carrier and E3 bolt this should outlast the owner and his kids.
the e3 bolt will only work in the sr15 uppers, which have different chambers cut for the knurled lugs on the e3 bolt face. this is not an e3 bolt and bcg, but a normal one meant for non-sr15 uppers.
thannx for having a good heart,more information from you guys
You have defiantly motivated me to become a gunsmith! I start at SDI for their associate's degree in firearms technologies! I know I will get some hate for this but I have some GI bill left and want to sue it for this degree. I have been unable to find a mentor close to me so this is my only option. This might help me get my foot in the door.
maybe KAC increased the 3 bore tolerances on the sandcutter for reliability in sand/ heavy fouling? just a thought
Outstanding! This video helped me big time. Subscribed and contacting Knights Armament.
Was this your BCG?
@@floridaredfishin8209 No. I had one just like this and had to send it back. The gas key came loose.
You're the best bruh!
Great video sir.
This is an incredibly educational channel!! I would love be able to do this for a living. I’ve always heard when you do something you love for a living that is not work. If I could do this then I’d never work a day again in my life.
Wealth of knowledge thank you very much
Great video sir I really wish I could come join you at one of your classes but unfortunately no money for plain flight ✈️ & plus the number one I Reason no money for your class but please keep making the videos very interesting lots of great info
These are awesome -- I'd love to see comparison videos / BCG you recommend as "gas efficient"
It's not as big of a deal if it's not the most efficient, especially because a crazy large number of AR's on the market are grossly overgassed so it actually kinda helps. But for a well gassed AR I think I remember him doing a couple new BCM's that passed with flying colors, one of which was his own. There are others but aren't coming to mind. Also as you use them they will obviously wear and those tolerances will get bigger as time goes on, but as long as your gas key is done right and there's no real leaks it should run fine if there's no other real problems
Forward control designs BCG have always done amazingly as well. Watched this entire catalog of bolt carrier group testing and FCD has had extremely tight tolerances. Building my first AR-15 and still deciding between LMT enhanced bcg and Scionics/FCD.
Would not have expected that on a KAC rifle. Wow
I don't believe the rifle was kac just the bolt carrier.
there are always going to be mistakes made, but it is interesting to see a KAC bolt carrier messed up like that i agree. I'd still trust a carrier from KAC but this is something to keep an eye out for now that we see at least one instance of this happening.
Great content and good to know.
Wow...nice work!
Good job. Great video
Best video work in the game! Great angles
You just made my day! Thank you!
@@onna-day7047 your welcome. Keep up the good work. 👍🏻
Another great video .
Oof. Would not have expected that from a KAC carrier...
People should keep in mind that most individual firearm parts are inspected on the AQL system. Brands that commands a higher price will inspect a higher percentage of parts, but most parts will still be sent through without inspection if the batch passes QC so some bad parts can slip through.
if you actually look at kac parts with an educated perspective this isn't surprising at all.
@@JTTTTT850 can you elaborate
You should be more open minded. Price doesn't mean everything.
Could you do one on miss alignment of upper to lower receivers? such as chatter marks on the bottom of a BCG, really curious because I have sent back an AR 9mm for this three times.
Do you got videos going over parts youve seen that have a low failure rate? Basically an entire build?
This is why I stopped buying KAC stuff. I started noticing tolerances and QC started to slip, a lot. For the price premium, it's just not worth it. The E3 bolt is interesting, but the proprietary everything just doesn't make sense to me.
Good vid sir!
Fantastic vid.
Great video thanks!
That is freaking crazy.
What gauge are you using on the extractor?
I imagine you see all kind of issues with ARs I have a problem. I have a barrel that has a muzzle brake pined and welded. And I want to remove the brake and have it redone. It wasn't done right. What is the safest way to remove it so I don't damage the barrel.
Where can I get the gages you use?
What company do you use for these go no go gauges?
Chad, please forgive my ignorance. What is the deal with magnetism check on the firing pin and bolt? What would cause a bolt or FP to become magnetic? What problems would it cause?
If parts are magnetic and you shoot steel cased ammo, it possible that casing and projectile shavings can stick to operating surfaces. This can cause reliability issues.
This was awesome to see. If i was to buy one gauge for my rifles should it be the field gauge or no go gauge for the headspace?
I would get all three: go, no-go, and field. The go needs to fit in, if it doesn't stop using that rifle NOW.
If the Field fits, stop using that rifle, NOW.
No-go is the maximum as-new size, it safe to shoot even if the no-go chambers.
Each one tells you something different. If you only have the no-go, you won't know if the chamber is too tight or too loose.
Not to mention that I don't think you can buy them individually.
It's also missing the liquid gasket that's supposed to be between the gas key and carrier body
If it was banging wouldn't there be impact damage on the back of the gas key as well?
What brand are your no mar jaws?
Thx
Where does a person buy bore gauges like this used in the video?
It’s interesting that it’s taking the larger gauges, but doing it very consistently. It makes me wonder if they are doing that for a specific reason.
@ABlindMan1 would be my guess, too.
Quick question, which vice insert/blocks are you using? Keep trying to catch the writing in the videos but can’t make it out.
where can i buy all the gauges used?
Chad, maybe as part of your BCG autopsies, you could run compressed air thru the gas key opening, while the bolt is in, and check for leaks around the gas key w/ some mixture of soap & water?
I do this in classes with oil. I also have a jig that measures gas loss.
So, how well do those kac sandcutter BCGs work?
When they work and are in spec they’re great..
@@MyLonewolf25 that doesn't sound like a ringing endorsement.
I wonder how one of these would run in my sr-15
Great content! How does one contact you to have you inspect their firearm?
Quality Guru he said that the guy who he got the bcg from contacted him on the SOTAR Facebook group. Hope that helps! Good luck!
@@jefflemaster2850 Thanks for the intel.
Found it!
Doesn’t newer KAC rifles have the rounded bolt lugs? My older KAC does and I thought that was a feature they were proud of. The bolt here doesn’t have rounded lugs.
Also, my KAC bolt has a beefier extractor with dual springs. Don’t know if it is a KAC carrier with another branded bolt?
I think this Bolt is from BCM and not from KAC.
I dont think thats an SR-25 bolt. I own an SR25 ECC and my bolt is chrome like the rest of the carrier. The lugs are also rounded (as well as other stuff). I believe the owner of that gun is running a different bolt on that carrier. As far as I know, KAC is particular about parts from other companies being compatible with their stuff.
You are correct!
Can you run this in a bcm or Noveske???🤯🔫💣
Why is "field" worse than no go?
Field gauge is the final step before being unsafe. This is because if something fails the field gauge it is unsafe to use in any case, even in life or death situations such as in the "field". But if it passes a field gauge while failing a no-go then the item can be used but it will not be optimal. no-go is more for the purpose of ensuring a quality product while field gauge tests the safety of a product.
Great videos but why don’t you ever respond to questions people ask you?
There was a group created to help answer all the questions.
facebook.com/groups/sotar/?ref=share
Everytime he inspects KAC they are sloppy
This is why u DO NOT BUY EXPENSIVE PARTS SECOND HAND. EVERYTIME U BUY EXPENSIVE STUFF SECOND HAND YOU'RE GONNA BUY IT TWICE.
Cheep bolt bolts.
That e3 bolt is proprietary it won't work on barrel extensions that aren't knights armament that being said that bolt isn't E3 its something else
I think he mentioned that the carrier is sometimes sold separately, because it may be going in a different rifle.
I own one of these and that definitely isn’t the E3 bolt from Knights!!!!
I bet most of the companies' products that are featured in your autopsies are not big fans of you
Or maybe they appreciate the "heads up" on their QA/QC process. Any mfr that cares about quality would appreciate learning about something that slipped through the cracks.
The Bolt carrier is KAC but the bolt, firing pin, extractor, and cam pin are not
Yes. I stated such in the video.
Marvin Pitts thanks captain obvious
That's not a KAC bolt...
Reggie Kanan and? It was clearly stated in the video. KAC sand cutters are sold as a bolt carrier without bolt, allowing you to use the bolt of choice in non KAC barrels due to barrel extension and bolt being proprietary to knights.
So basically my PSA is better than my KAC.