Bolt catch release lever problems

[budlight]

I bought an ar-10 308 kit. The upper assembly from one place and lower from another. The problem is that the bolt catch doesn't catch. The bolt carrier just slides right over. So I bought a NB even more expensive BCG thinking it would work and the same problem. manually or the last round doesn't stay open.

I've heard that not all AR-10's are made alike? What is the juries decision?

 

[budlight]

The 308 BCG only has a tiny corner that can catch the raised lever. After 30 firings yesterday it has scraped the finish of the lever arm, but never enough to catch. On my other ar's you can manually hold it and pull back the charging handle and it keeps the bolt open to show that the rifle is clear. simple push and it slams shut

 

[Dave in WI]

It's been my experience on the "AR10" platform that you stick with matched brand upper to lower. There is no "mil spec" for that platform and dimensions vary among manufacturers. DPMS over DPMS, or Palmetto over Palmetto, etc.. I've had the same issues mixing, but never when matched brands. HTH

 

[Frog4aday]

Is this DPMS? AERO-PRECISION? PALMETTO STATE ARMORY? ARMALITE? That would be helpful info. Best bet is to try a different bolt catch. Some Aero kits had fragile/bad bolt catches but that's been a few years ago now. Maybe you just got a bad one? Others have problems because they put the wrong spring & buffer in their guns, so you might google that and take some measurements of your gun to see if all is well in that dept.

 

[budlight]

I came across this:

The AR-10 vs. the LR-308: What's Different?

This guide compares the DPMS LR-308 and ArmaLite AR-10 platforms. Learn about compatibility, how to configure your rifle, and see cost/performance comparisons.

www.80-lower.com

 

[budlight]

The upper is a Aero Precision LR-308 Ar-10 M5 .308 The lower is a AMT AR-10 Gen 1 DPMS Anodized Billet Lower Receiver.

The problem turned out to be the lower reciever is too tall on the rear binding the charging handle. I can NOT even mate my lowers to a PSA upper. You can't even get the rear take down pin in. The PSA lowers from a friend operate correctly.

I have a been talking to American made tactical. The fix would be to machine a few thousands of an inch off the upper rear buffer tube area.

 

[Buck Fever]

It's been my experience on the "AR10" platform that you stick with matched brand upper to lower. There is no "mil spec" for that platform and dimensions vary among manufacturers. DPMS over DPMS, or Palmetto over Palmetto, etc.. I've had the same issues mixing, but never when matched brands. HTH

This.

I really like Aero enhanced receivers. My minimum is matching upper, lower and partial LPK. I usually add a handguard to match an enhanced upper but you could go standard to increase your choices with other manufacturers high profile DPMS LR308 handguards.

Beside that, I rarely have fit or compatibility issues using good LR308 compatible parts. For a carbine stock I like the AR10 style and usually buy a POF P308 buffer kit but those are the only AR10 style parts I use.

I usually use Toolcraft BCGs in NiB, Ion Bond or Nitride finish. They all work with my Aero receivers and LPK bolt catch.

One more thing, I always prep my LPK a bit to make sure everything works smoothly. A burr or a little grit in the wrong place can jam things up, so take a few minutes to dry fit, clean and oil.