anti-rotation pins AR15

[arjohnson]

Old wives tail,or internet lore. Prove where it is more harder than a DI system. It doesnt. Your punny 22 is harder on the pins than a 458 socom ,Or even the 556 rd is pure hogwash. The blowback in 9mm might have a slight increase, but it also; due to the blowback design have more felt recoil than the 556. we are talking about a sheared pin ,not just pin rotation. The pin more than likley, as stated by another poster had a flaw, which failed. it had nothing to due with blowback.

The OP's pic should be proof enough that a 22 can and does break hammer pins. I have also seen it many other times in numerous threads on AR15.com. I talked to one of the leading 22AR manufactures about some issues I had with mine, this also came up about using KNS pins in the direct blowback guns for this very reason.

As I said go do some research on AR15.com, talk to someone who manufactures them, I did all these things, it's not uncommon.

[arjohnson]

Wrong again, I have had my pins rotate out on FA 556. When firing on fa over time the pin holes can get oblong or just plain larger, and the pins will walk out.

Just as with any moving part, over time with lots of rnds fired these parts will wear out. I can see where FA fire can do this to a receiver, but your talking about a shit load of shooting before a receiver gets oblong or over sive FC holes.

I can also see if you have a valuble NFA item and you want to take an extra step to protect it, KNS pins are good for this, but's it's not a neccessity.

[cdi]

I have seen hammer pins break from mixing the wrong combination of bolt carrier, firing pin and hammer. Colt guns have gone through a multitude of parts changes over the years and their parts show up in all kinds of AR's.
Never thought about the stress from a blowback .22 kit snapping pins, though.

I have noticed that incompatible parts like those above will sometimes transmit the shock they receive on firing through the trigger. You can feel it in your finger when the gun is fired, it can be downright painful.

If the pins are walking out of your AR (even in full-auto) the most likely cause is mis-assembly of the hammer spring, defective hammer spring or missing/broken J spring. If the holes in the receiver are out of round, take a good look around to determine how they got that way.

[gold cup abuser]

Well let this Army trained armorer chime in a bit.

In our parts kit are hammer and trigger pins and they are all sized differntly,this is do to frame stretch that happens on military rifles that are decades old and have been through hard use.

As far as hammer and sear pins breaking I would be on substandard parts pawned off by a less than honest manufacturer on a civillian AR.

I use a 22 conversion on both my M4gery's and have ran about 1k rounds through both and so far no issues with eithe my Stag built or Rock River built M4's.

But this is a warning to the OP to go out and stock up on some spare parts and to do so right away.

If the parts are cheap then you just might get what you pay for.....

The KNS pins in a civilian use AR are good for a match trigger type setup, or for extra security in having those pins rock out of position, but I would just stock up on on more spare parts instead.