I took my K22S out to the range today for the first time, here are my results
It was -3C out and my fingers were starting to get cold so I didn't get a chance to try the heavier spring like I wanted, but I ran one mag of the following through in this order
CCI Mini-mag 36 Grain hollow point 1260 FPS No issues
Federal Champion 40 Grain Solid 1240 FPS 1 FTE
CCI Velocitor 40 Grain Hollow Point 1435 FPS 2 FTF (Rounds were chambered but no firing pin strike, removed the mag, and re racked the slide and those rounds fired)
Winchester White Box bulk 36 Grain Hollow Point 1280 FPS 3 FTF so I ran a second mag through except this time I had 2 FTE's.
Remington Golden Bullet 36 Grain Hollow Point 1280 FPS 3 FTF's same as the Velocitor's rounds fed properly and were chambered but no pin strike.
Just as a comparison, my buddy brought his M&P 22 which he's had for a while and it had no issues with the Remington's or the Winchesters so I'm not sure how scientific my results are, if the K22S needs to be broken in, if I need to use the heavier spring, of if the cold was affecting it, I do know that the cold was affecting my fingers which is why I didn't try the heavier spring.
I hope this helps some of you out, the next time I go out, I'll do a magazine of each using each spring and post the result, but it may be a little while till I get to it as I'll want to do that when it's a little warmer out.
Had a chance to take the K22S out today. It was a little warmer than last time at 11.5 degrees but raining
Here's the ammo I used and my results
These are using the lighter Spring:
1 Magazine of CCI Mini-Mags 36G 1260FPS 1 Failure to Fire, round was chambered but no pin strike
1 Magazine of Federal Champion 40G 1240FPS 0 issues
1 Magazine of Winchester White box 36G 1280FPS 3 Failure to Fire no pin strike and 1 feeding issue it ended up bending the round almost 90 degrees.
1 Magazine of Remington Golden Bullet 36G 1280FPS 2 Failure to fires again no pin strikes, rounds were chambered leave the round chambered and removing the mag I was able to fire these 2 rounds
I swapped out to the heaver spring for the following tests:
1 magazine of CCI mini-mags no problems
1 magazine of Federal Champion 1 Failure to Fire, same as above round chambered but no pin strike
1 magazine of CCI Velocitor 40G 1435 FPS no problems
1 magazine of Winchester White box 4 Failure To fire
1 magazine of Blazer 22LR 40G 1235 FPS no problems
So the heavier spring seems to work better but mine really doesn't like the Winchester bulk which is fine as my ISSC MK22 shoots it without any problems. For the most part all my failures have been identical regardless of the type of ammo. The round chamber properly but the firing pin doesn't strike. I'll try to take out again later this week and I'll keep you updated with the results.
I'm interested to see if any other K22S are seeing the same thing as me with the rounds being chambered but no strike and to which spring they're using.