Bolt locking issues

[GunFighter98]

+ 1 on checking the bolt catch.

[trlcavscout]

Most of these I have seen the spring was mixed up with the disconnector spring or was installed wrong. Do you have another spring to try?

[товарищ]

H buffer is the heaviest I use on a mid-length. H2s are for CAR gas guns and/or suppressed guns.

I'm going to order a standard today and see how it works later this week. Thanks.

Most of these I have seen the spring was mixed up with the disconnector spring or was installed wrong. Do you have another spring to try?

Nope, I keep my FCG parts away from everything else. I have a separate lower with a DD LPK and carbine RE, so I'm going to throw the H2 into that and try it with my upper. I wish I would have remembered to bring it a few days ago.

[Todd00000]

I had the nipple on the bolt catch, the protrusion that the mag follower comes in contact with, break off. Check your bolt catch with your upper off and an empty mag in the well. It's easy to miss.

[ASH556]

My money's on short stroking/H2 buffer. Run a std H buffer and see what happens.

[jstyer]

My money's on short stroking/H2 buffer. Run a std H buffer and see what happens.

+1 on this... I'd definitely run an H buffer before diagnosing anything else. It's a cheep/quick check.

[товарищ]

I got around to shooting again today and now I have a new problem.

I tried a BCM standard & H buffer. Both buffers will lock back only 90% of the time.

Internals are fine, nothing is broken or defective. Ammo used was from a different lot of Federal M193. I ran 30 rounds of 75gr .223 Hornady TAP and the bolt locked back for all of the rounds.

I've never had a problem with Federal M193 being underpowered (and I don't think the ammo is at fault here), so this is kind of weird.

[Rifleman_04]

I recently replaced a slightly out of spec LMT bolt catch. Might wanna give that a try if you have a spare laying around.

[GunFighter98]

I recently replaced a slightly out of spec LMT bolt catch. Might wanna give that a try if you have a spare laying around.

Thanks, works flawless now!

[товарищ]

I recently replaced a slightly out of spec LMT bolt catch. Might wanna give that a try if you have a spare laying around.

I don't have a spare, but I'm going to retry this tomorrow with a DD catch. I should have just stuck with a DD LPK.