Third bolt release on AR-15

[vinniedelpino]

I'm stumped. I'm on my third bolt release in two years and less than 5k rounds. Upper/lower are both billet spartan receivers from Joebob Outfitters. The bolt release inlet was a little tight initially, so i lightly filed until the part moved freely with no resistance (save for the spring) after I broke the first one. Both broken bolt releases were from Aero and the third that's going in now in Spikes. They're breaking right below the paddle.

Any ideas? I'm definitely hard on the rifle, but there has to be something else going on here.

 

[MOUNTIC]

Not that Areo are bad parts, but I would be putting in a Forward Controls one if I had issues. Machined from solid piece of 8620.

ABC/R v3 (Augmented Bolt Catch / Release)

 

[simonp]

Ive used Geissele on my builds and thousands of rounds later have never had a single issue.

Are Aero parts MIM?

 

[B y r o n]

I'm stumped. I'm on my third bolt release in two years and less than 5k rounds. Upper/lower are both billet spartan receivers from Joebob Outfitters. The bolt release inlet was a little tight initially, so i lightly filed until the part moved freely with no resistance (save for the spring) after I broke the first one. Both broken bolt releases were from Aero and the third that's going in now in Spikes. They're breaking right below the paddle.

Any ideas? I'm definitely hard on the rifle, but there has to be something else going on here.

When you say you "lightly filed" are you talking about the lower receiver or the bolt catch?

What parts make up your bolt system? M16 , AR15, lighter or heavier bolt? What weight buffer and standard or custom spring?

Are you running factory ammo or handloads? What bullet weights and velocity are you seeing?

What I'm trying to determine is if the area filed caused a defect that may be contributing to the breakage.

The other questions are related to the speed/force of the bolt into the bolt catch that could be causing the breaks.

 

[vinniedelpino]

When you say you "lightly filed" are you talking about the lower receiver or the bolt catch?

What parts make up your bolt system? M16 , AR15, lighter or heavier bolt? What weight buffer and standard or custom spring?

Are you running factory ammo or handloads? What bullet weights and velocity are you seeing?

What I'm trying to determine is if the area filed caused a defect that may be contributing to the breakage.

The other questions are related to the speed/force of the bolt into the bolt catch that could be causing the breaks.

I filed the lower receiver with a jewelers file. The bolt catch was in tact. I can't imagine I took more than a thousandth, maybe two. It was awfully tight beforehand.

Toolcraft FA carrier, H buffer (I believe) and standard spring.

It's a 300BLK, by the way. 90%+ of rounds through the rifle are 209gr hi-tek subs over a pinch of CFE-BLK. I'd have to check my load data as these things were loaded a while ago. They're definitely subsonic though.

 

[Rerun7]

How are you releasing the bolt? Pushing it with your thumb or using your pimp hand slap?

 

[vinniedelpino]

How are you releasing the bolt? Pushing it with your thumb or using your pimp hand slap?

I beat on that thing like a rented mule.

I'm mostly shooting fast at short range and can get a little excited at times.

Sounds like the billet part referenced above might be worth a shot.

 

[B y r o n]

I filed the lower receiver with a jewelers file. The bolt catch was in tact. I can't imagine I took more than a thousandth, maybe two. It was awfully tight beforehand.

Toolcraft FA carrier, H buffer (I believe) and standard spring.

It's a 300BLK, by the way. 90%+ of rounds through the rifle are 209gr hi-tek subs over a pinch of CFE-BLK. I'd have to check my load data as these things were loaded a while ago. They're definitely subsonic though.

Being sub sonic loads and standard components I can't see anything wrong. I know it is to late this go around but next time you need to modify a part, do it to the least expensive part in case a mistake is made. Cheaper to replace a bolt catch than go through the hassle of replacing the lower receiver.

 

[Ernest 5.56]

You could try inspecting it after several hundred rounds for abnormal wear.

 

[Shifty6BR]

Been running a Seekins on a blowback 9 sbr for some time after going thru a few standard paddles initially. The Seekins are beefy.

 

[reelserious]

Wilson combat sells billet steel ones. investment cast and mim are all crap IMHO

 

[Rerun7]

I beat on that thing like a rented mule.

I'm mostly shooting fast at short range and can get a little excited at times.

Sounds like the billet part referenced above might be worth a shot.

Yep, if you’re gonna beat on it then get better quality parts.

 

[reelserious]

When you buy a lower parts kit for like $50 it cost them probably $5 to make it so when you divide it up with all the parts your bolt catch etc are like .25 parts. For that money gotta be mim or cast. For any serious rifle go with billet .

 

[bfoosh006]

You might check the over travel on the cycling mass.... see how far your bolt is moving past the bolt catch when fully compressed into the buffer tube.
You can't do this with the charging handle only, so.... lock the bolt back, then use a blunt stick to press the bolt face as far back as you can.

IMPORTANT !!! Wear safety glasses... you don't want to launch your stick into you eye, since you depressing the bolt face will release the bolt catch.

If memory serves me... you "want" 3/16 ish of an inch max over travel.

Much more and the mass has enough oomph to smack the bolt catch pretty hard.

FWIW... it is a common issue in AR PCC's, breaking bolt catches that is.

 

[strikeeagle1]

I know it is to late this go around but next time you need to modify a part, do it to the least expensive part in case a mistake is made. Cheaper to replace a bolt catch than go through the hassle of replacing the lower receiver.

Exactly. Gunsmithing 101. Always modify the least expensive OR more readily available part, first.

 

[TheOE800]

You might check the over travel on the cycling mass.... see how far your bolt is moving past the bolt catch when fully compressed into the buffer tube.
You can't do this with the charging handle only, so.... lock the bolt back, then use a blunt stick to press the bolt face as far back as you can.

IMPORTANT !!! Wear safety glasses... you don't want to launch your stick into you eye, since you depressing the bolt face will release the bolt catch.

If memory serves me... you "want" 3/16 ish of an inch max over travel.

Much more and the mass has enough oomph to smack the bolt catch pretty hard.

FWIW... it is a common issue in AR PCC's, breaking bolt catches that is.

I was waiting for someone to mention BCG length and/or travel! Good good.

 

[MarshallDodge]

Is there a metal burr on something that is rubbing where the release is breaking?

 

[nikonNUT]

I was told to shim the buffer tube with quarters (You can buy a real shim kit but it costs more!) until I had an 1/8" gap between the bolt pulled all the way back and the catch otherwise the bolt will beat the catch to death.

 

[reelserious]

I was told to shim the buffer tube with quarters (You can buy a real shim kit but it costs more!) until I had an 1/8" gap between the bolt pulled all the way back and the catch otherwise the bolt will beat the catch to death.

$1.75 in quarters or you can buy an aluminum spacer for like $ 15