Hi, new here.
Last Saturday I picked up both the SIG522 and the SW15-22 for my two boys. I really pushed the 15-22 as I have no SIG experience (and all my SW are awesome, including my 22A-1 which eats CCI and Federal perfectly, although I read a lot of complaints about it), and even though Nic (14) really wanted the 522, I had real reservations. Cam (12) got the 15-22.
Both guns were cleaned before taking to the range.
Sat at range, SIG 522 eat everything we put in it. CCI Mini Mag, Federal bulk pack, and then the ultimate test, it ran a whole mag of the nasty Remington Golden bullets, no problem (will never use them again, but was curious).
15-22. First 100 rounds CCI Mini Mag. No issues at all, feed perfect. Decided to try the federal bulk pack. These work perfect in the other 6 .22LR we have. Loaded only 10 in clip. 4th had fairlure to eject (catching the shell in the receiver cover). Cleared, all well until the 9th round. Large BANG (not the good kind). It really scared my 12 year old who was shooting at the time. Opened the chamber and there is a shell that only went about 1/2 into chamber, yet still fired. Most of the sides of the back of the shell were blown out. A spring fell out also. So this was taken back to the dealer (on Sun the gun show was still going on). I'm sure it will be corrected, but I will wait for weeks.
It was one of the new models:
S&W M&P Spec Edition
SN# DTX6xxx
Model M&P 15-22
And the boys now hate that gun. Only 109 shots fired and it's gone. I guess it's mine now

. So when we took the 15-22 back, I also him a SIG (actually P226 pistol).
It's only a sample of one, so it's not statistically significant; but it's irritating. I also wonder about a design that will allow it to fire with round only 1/2 chambered.
Anyway, one day I will get my (it's mine now

) SW 15-22 back. So far another 1025 rounds through the SIG522 and not a single issue.