HELP, 15-22 not resetting hammer correctly

[tlimcher]

Shot about 500 rounds through my new M&P 15-22, a issue I have come across is the trigger would not reset occasionally, usually on the second shot of a new mag. I've taken it apart and can't see anything out of the ordinary besides a scrape on the back on the bolt in that U cut. I'll post a pic in the attachments. Any idea how to fix it? Thanks!

 

[SMSgt]

Some basic questions:
Did you clean and lube prior to use?

What brand and type ammo did you use? Not all .22 ammo is equal. I find CCI 40-grain MiniMags work when others won't.

Have you tried a different magazine?

.22 ammo is dirty. My Advantage Arms .22 conversion kit will run fine until about 100 rounds and then must be at least wiped clean to function properly.

 

[tlimcher]

I cleaned it before I shot it but not the trigger mechanism. I shoot 22 mini mag CCI, and on two different mags it's done the same thing.

 

[Luger9x19]

Did you clean the bolt guide assembly? Clean it good, check it for burrs and put a small amount of lube on it. I would also clean the guide rod and spring and add a drop of oil.

 

[tlimcher]

I cleaned it and wiped it with rem oil, I haven't shot it since then but I will today and let y'all know! Thanks!

 

[tlimcher]

I shot it today, worked great until the 3rd or 4th mag.

 

[TX-Dennis]

Loose or walking pins?

I think I would call S&W and let them sort it out. Won't cost you anything, and you'll have it back in a week or two.

 

[Luger9x19]

I think I would call S&W and let them sort it out. Won't cost you anything, and you'll have it back in a week or two.

What he said!