Thanks you guys are great. I will check and hopefully get her running right.
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Thanks you guys are great. I will check and hopefully get her running right.
Check the spring length if you can or even try a different USGI one from Colt. If your spring is too long or too stiff it can cause short stroking.
One of the perils of buying commercial parts is they are all not made to one standard.
When you rack the BCG do you feel any specific spots where it feels like its rubbing on something?
Check around the FSB for gas leaks. A little bit of residue is normal but if it looks like there is powder burns you are probably leaking too much. Also why you are there check to make sure you have a gas tube pin in the FSB. It will be on the horizontal part of the A.
Check the carrier key for tightness.
They are right....gas rings on the bolt do not need to be staggered. Its a bit of a myth. Also make sure you have 3 of them, and that the bolt is somewhat tight in the bolt carrier. If it feels really loose its probably time to replace them. Even new rings can be bad...
And yes shoot it with some good 5.56 pressure ammo (M193 or M855). Worst case the rifle length system is just a bit undergassed to where that 'crap' UMC wont cycle it reliably and you need to use some hotter stuff. It technically should cycle that ammo but its on the bottom end of ammo regarding use in an AR due to being so weak. It does have a 5.56 chamber, no?
The ammo may be weak, but it should work with that ammo. I have run it through my HK416 which has an even heavier spring and buffer without a problem.
Definitely try stronger ammo, though.
If your buffer is longer than the carbine buffer, it's a rifle buffer. There will be a roll pin in it, you can push this out and remove weights. It's just something you can do to tune your gas system. But you should check the things the other guys mentioned, as you want to make sure everything is working properly before tuning it.
Definitely check the fsb. I had the same prob with one of my ar's. Fired it from the hip one day at the range and saw a small amount of gas leaking from my gas block. That cured my 'clicking' problem after torquing I correctly. Like the others said check your bolt carrier as well. Is it just barely staked as I call it?