Bolt catch on a AR10 build

[Dougy Fresh]

Hi friends,
I have a bolt catch on a AR10 build that seems to pivot as it is suppose to but it will not hold the bolt back. I think I need a fresh set of eyes on it. Thoughts or ideas?

 

[Rebel_Rider1969]

Shot it yet?? Make of upper and lower? Make of bolt?
Hopefully this isn't a lr308 vs ar10 issue.

 

[Bowhntr6pt]

Whose bolt catch did you use?

 

[Dougy Fresh]

Shot it yet?? Make of upper and lower? Make of bolt?
Hopefully this isn't a lr308 vs ar10 issue.

Haven't shot it yet.

80Percent Arms Black Anodized Billet .308 80% Lower Receiver

CMMG MK3 .308 Lower Parts Kit​

BC-10 | .308 Upper | 20" 416R SS Straight Fluted Heavy Barrel | 1:10 Twist | Rifle Length Gas System | 15" MLOK Split Rail (DPMS Gen-1 low profile pattern)

 

[Dougy Fresh]

Whose bolt catch did you use?

Came with the Bear Creek Upper
BCA AR10 bolt carrier group

 

[Dougy Fresh]

Whose bolt catch did you use?

BC-10 | .308 Upper | 20" 416R SS Straight Fluted Heavy Barrel | 1:10 Twist | Rifle Length Gas System | 15" MLOK Split Rail (DPMS Gen-1 low profile pattern)

 

[Bowhntr6pt]

This is the problem with mix-matched stuff in the large frame game.

Just as an elimination point, compare the bolt catch to a standard AR15 bolt catch.

Maybe the recess for the catch is not deep enough... is it a case of the catch not rising up enough to catch the bolt?

When you pull the charging handle does the bolt carrier group travel back enough for the bolt catch to rise up?

 

[Raven]

Does it do it with an empty mag inserted? Switch mag brand and try it. Does it do it without a mag inserted?

 

[Hinote]

Exact same thing on a Delton lower with any Aero upper and the bolt won't hold open on the last round. The large frames are super picky when you mix manufacturers even if they say DPMS pattern rifle. I bought the Delton thinking I could just build multiple uppers and swap things around as I wished. Nope.

 

[Dougy Fresh]

Whose bolt catch did you use?

Sorry for the delay. The bolt catch came with this kit from 80% Arms

CMMG MK3 .308 Lower Parts Kit​

 

[Rebel_Rider1969]

Could be spring and buffer issue, maybe? (Too long) must use 308 ones. H3 weight. Ymmv

 

[Dougy Fresh]

Does it do it with an empty mag inserted? Switch mag brand and try it. Does it do it without a mag inserted?

Won't stay open with an empty mag. Using an Amend2 mag. That's all I have at the moment.

 

[Dougy Fresh]

Could be spring and buffer issue, maybe? (Too long) must use 308 ones. H3 weight. Ymmv

Aero
M5 .308 Carbine Buffer Kit

SKU: APRH100158C

 

[Raven]

Won't stay open with an empty mag. Using an Amend2 mag. That's all I have at the moment.

Stay away from plastic and go with coated stainless steel mags. Duramag is good stuff

 

[Rebel_Rider1969]

Stay away from plastic and go with coated stainless steel mags. Duramag is good stuff View attachment 186160 View attachment 186161

Magpul work good too. Ymmv

 

[Rebel_Rider1969]

Aero
M5 .308 Carbine Buffer Kit

SKU: APRH100158C

Damm. I was hoping it was the buffer,spring.

 

[Dougy Fresh]

Sorry for the pause in seeking help. Had to handle work and grandkids stuff. So I purchased a couple of Duramag SS mags and they don't hold the bolt back when empty either. Are the bolt catches for an AR15 and AR10 the same? I was thinking of replacing the bolt catch but I only have a ar15 catch laying around.

 

[Hinote]

An AR15 bolt catch will work on LR308 patterned rifles in theory as they used to be shipped with them. It's a crap shoot with 308 stuff though.

 

[Dougy Fresh]

An AR15 bolt catch will work on LR308 patterned rifles in theory as they used to be shipped with them. It's a crap shoot with 308 stuff though.

Thanks for the info.

 

[Dougy Fresh]

Would any of you experts like to put eyes on it? I live in Milton. Can meet you or you are welcome to come by my home.
I guess my next step would be to email 80% Arms and copy Bear Creek Arsenal to get their ideas.