AR started doubling

[Tim K]

The floating firing pin combined with all the other variables can result in some doubles here and there.

Timney triggers, XP buffer springs, low mass buffers, extra-mass buffers, Federal primers, brass shavings in the FP channel. VERY solid bracing, like bags or a lead sled can also induce doubles.

Interesting. I almost never shoot off a bench, and it only doubled when I moved to the bench. I'll try it again and see if the problem persists in other positions. It was squeaky clean, so that wasn't it.

[MarkCO]

Interesting. I almost never shoot off a bench, and it only doubled when I moved to the bench. I'll try it again and see if the problem persists in other positions. It was squeaky clean, so that wasn't it.

If that is your issue (it is actually not uncommon), you can cut a coil off the buffer spring, get a reduced power buffer spring, use harder primers or use a Titanium firing pin. You can also reduce the propensity by adjusting the cycle speed: adjusting the gas down or reducing the powder charge.

[C Ward]

Throw the Timney in the trash and put a JP in it . Timney's have a known track record of this issue .

Don't monkey with the operating system until its a last resort , messing with carrier weight , springs , LW buffers , and such is unneeded in my opinion on a rifle with marginal recoil to start with .

[Tim K]

I don't know that I'll throw it away, but I did just call Timney and it's evidently an old design that has since been superseded for just this problem. They are replacing it at no cost.