Brought my brand new 15-22 to the range tonight for the first time. Shot a total of 400 rounds through it.

First 240 rounds were Winchester M22, and got about 100 rounds in when I had a FTE which took about 5-6 pulls on the charging handle to actually clear. Other than that shot great with this ammo.

Then switched over to some Federal Auto Match. 160 rounds of that. Within the first 50 rounds though I had 2 stove pipes. I could also hear that quite a few of them were going sub-sonic and it almost seemed to be "soft" shooting when they were going sub. Im thinking this is an ammo issue rather than an issue with the rifle. This ammo also seems a little smokey.

What are you guys thinking?

3 of 4 of my 15-22's have issues with Fed Automatch. I feel the same as you, they shoot much softer then any other ammo of the same FPS. I'm thinkin' they use a slower burning powder for this load.

I just use the Automatch in other guns since they seem to gobble them up.

Glad its not just me. Picked up a few boxes of the stuff at bass pro for .05/round and was hoping that the 15-22 would gobble it up. I tried it in a Ruger Mark II target pistol and it did great in that but still went sub-sonic on a regular basis.

I have found using the recommended ammo brands listed with the M&P 15-22 owner's manual to be the best for this. This AR seems to be a bit finicky overall. I use the CCI Mini mags and Stand. Velocity rounds, but the others on the list are fine too. The CCI brand seems to be a 'cleaner' round, so not as dirty as other brands.

I recommend trying the CCI!

KH

I was afraid the issues I was having was ammo as well (Federal Auto match). I switched to CCI min-mag but had the same issue. Sent the rifle back to S&W. The invoice (n/c) said they repaired the ejector. Back out to the range a couple days ago. Couple hundred rounds later only 1 FTE and that was with CCI. No issues at all with the auto match.

I just bought 4 bricks of CCI mini mags at cabelas, will try them out when im at the range this weekend

The auto match was ejecting fine(Other than the stove pipes), I just felt like it wasn't shooting as hard as other ammo in the same FPS range. I felt like it only stove piped because it wasn't send the bolt all the way to the rear and was slamming home faster than other ammo which sent it all the way to the rear.

I took the entire rifle down and cleaned it really well and lubed it back up, im still going to try the auto match in it as I have 500 more rounds left.

Two thoughts:

Make sure the chamber is clean. 22's leave a hard carbon deposit in the chamber(s) that's easy to polish the surface of rather than really getting it out.

Check the ejector alignment. It's discussed here with good pics at around post #30: New 15-22 Jams Like a Mother