not sure how but the hammer spring moved over on top of the trigger return spring and woall la the pin walked out..


does any one have any idea how this would happen,, this is the 7th ar-15 type rifle i have owned and this is a first for me

It is possible the leg(s) of the hammer spring were not actually in the groove(s)?

Pictures would help me understand what you mean. The hammer spring legs are supposed to be on top of the trigger pin.

Evening nathantc

The hammer spring tails sit in grooves in the trigger spring right next to the receiver edges (that's what keeps the trigger spring in place) . Were they properly placed in those grooves at last install?

If the spring was installed properly then it sounds like the hammer spring worked it's way out of one of those grooves & onto the pin top therefore allowing the pin to migrate sideways.

Are you running a weaker hammer spring? If so that might not allow the hammer spring to have enough tension on those tails to keep it solidly in the trigger pin groove.

Or your pin might have a loose fit in the receiver holes allowing it to wobble around. I had to make oversized hammer & trigger pins for my 15-22 as the originals were quite loose in the receiver holes.

All was right,, this is a new rifle and just past the 550rd mark,,, the springs were where they were suppose to be but some how moved,,, and yes there is a slight bit of play in the receiver holes.... Over sized pins or some anti walk pins are for sure next on the list,,, after I eat I will recreate what the springs did and take a pic

ok before any one ask,,,,, in all my AR-15s all i use in all moving parts is Hoppe's No. 9 "DRY LUBE" thats what all the white is
useing this makes cleaning a snap


This is the Performance Center M&P 15-22 with the 2 stage trigger,,, all of the FCG and springs are stock S&W




that said here is what it is supose to look like




and this is what it some how did all on its own,,,, i have never (untill now) removed the FCG from this otherwise new rifle.

maybe i got it that way from S&W and some how just didnt notice when i did the first clean & lube

That is the most likely supposition. Nice looking piece, BTW.

What's all the crud inside the receiver? Looks like you might want to take an air compressor or canned air to it.

dry lube that got thrown around after i fired it

and yes i love this rifle,,, it sure is sweet

Messy stuff.

How much dry lube did you spray in there? That looks like a mess.

Just to clarify: The pin that both retains the hammer and is it's pivot walked on you for no apparent reason?

If so...

Check the hammer's "J" pin. Look into the pivot hole where the pin is pushed through the hammer. You should see a pin in there. The "J" pin helps retain the hammer pin, keeping it from walking.

I was shooting the AR I built, and all of a sudden the hammer retaining pin started to walk. I pushed it back in, fired some more, and it kept walking out.

I cleared & safety checked my AR. When I tilted it to the side, ejection port facing up, the hammer retaining pin just fell out.

Turns out the hammer's "J" pin failed. Replaced the hammer and all is good.

it was the trigger pin,,, not the hammer pin

Not much at all,, and I applied it to the part while they were out side of the rifle,,,, when it dry's its like powdered sugar,,, so after firing 100rds I sorta goes every where,,, nice thing is a dry rage cleans it and the power blast from the ammo with ease.....

Wet lubes are far more mess only u can't usually see the oil till it collects all the grime

Sorry, but there is no physical way for this to happen "by itself." The hammer spring ain't gonna jump on top of the trigger spring.



-- Chuck

i dont think so either but it did happen to me,,,, like i said, maybe it was like that when i got the rifle and it just took that long for the pin to walk,,, but i pay close attencion when cleaning my rifles and i dont see how i wouldnt have noticed

Don't worry, the spring leg position is easily missed during assembly. One of those things ya gotta check. Could easily have come from the factory like this.

Only one groove at the end of the trigger/hammer pin and it doesn't matter with an AR15 which end the groove goes on as both hammer legs rest on the trigger pin so one of 'em should engage. Both ends should be against the receiver wall (on each side). There's less room for the spring legs on the M&P15-22 as the receiver walls are thicker.

-- Chuck