AR Question

[T.J.]

its not the mags ive tried several different brands including one HK mag. it might be the spring on the bolt catch, but like i said once i put it tight against my shoulder the problem pretty much disappeared. I also never had any problems with the PP 5.56 ammo

[nikon777]

Get a bolt catch spring from Brownell's

[John A.]

This could be caused from several different things. Though I don't wish to alarm you with the possible causes as it's probably just a spring. There's only one way to find out and that's with checking and possibly changing if necessary.

1. As has been stated, the number one culprit could be weak mag springs.
Though with several different mags, would be unusual to say the least with different mags all having bad springs.

2. Weak bolt hold open spring (as has been stated already)

3. Incorrect buffer spring installed
Carbine and rifle buffer springs are different size. The collapsible stock springs are shorter, though it's not unusual to find various lengths depending on the manufacturer. It's possible that it's just slightly longer (more tension) than spec.

4. Is the gun lubed properly? Most folks prefer to run wet

5. Improperly aligned gas block/gas port

6. fouled gas tube

7. gas key tight and staked?

8. badly fouled or out of spec buffer tube

9. slightly out of spec reciever or bolt carrier

[xdfan25]

That sounds like gas leakage , check the FSB area can you see any discoloration ?

Check the bolt carrier key , is it loose ? apply some aviation sealant underneath the key , put 2 screws back in the place and re-steak it.

If you manually pull the handle and it locks on the lever , it cannot be a weak B-catch spring.

Check for wear on charging handle and/or Upper Receiver

Hmm the last thing I can think of is to take the FSB off and ream the gas port to .065 (if you have m4 barr) , thats gonna help.

[Badshot]

You would think it there were any time of gas leakage issues he'd have feed/cycling issues.

[xdfan25]

not necessarily , i had a similar problem and i found out the gas port to be undersized . but before i was blaming the magz and springs , but you can simply check them.

[Badshot]

So T.J. what's the good word here?

[T.J.]

im gonna say it was underpowered ammo i switched to a little better brand of ammo and havent had any problems.

so im thinking the Aguila i was shooting was just a little under powered, ive only had one instance with the HSM that did not lock back and i am thinking that i did not have a good shoulder weld on that round.


i picked up 300 rounds of Remington the other day and i think im going to head out this weekend and sight in my new AP and see how the Rems work in it.

i also got me some long pipe cleaners and cleaned out the gas tube. so we will see.

[Badshot]

Coolness... but remember, the gas tube doesn't need to be cleaned.. there are how many pounds of pressure blowing back through that wee bitty tube that it's EXTREMELY unlikely that anything that is in there is going to stay there

So the caution is don't over do it if you're going to stick things down in that tube.

[Pugs]

Originally Posted by xdfan25

If you manually pull the handle and it locks on the lever , it cannot be a weak B-catch spring.

I disagree with this comment. Manually pulling the charging handle cycles the bolt more slowly than it does when actually firing the weapon. The slower cycling of the bolt gives a weak bolt catch spring more time to engage the bolt catch.

But then again, I don't know diddly-poo and could be wrong.