I have a p226 in 9mm that has run perfect with over 2500 rd. I bought a Sig 22lr kit but every few rds the slide stops just short of going into battery- I have 4 mags an it happens with all of them even with only 6 or rd.(btw the gun was very clean and lightly oiled slide). The recoil spring is new, does anyone make an extra power spring for the .22lr conversion? I was using cci mini mag. Tried águila and had the same result.

You mention the recoil spring being new. Do you still have the old one and if so does it still do it with it.

Yes but with the old spring it’s the first 2 or 4 shots where the slide will not fully go into battery, if I only load 2 or 3 rd it’s usually ok. That’s why I thought a new spring would fix it.

I have owned one of these conversions since they came out. I have experienced the issues you described in the past. I have well over 10K rounds on mine.

Did you buy the lit new or used?

Here are the steps I take:

Even though failure happens with all magazines, check the magazine spring and follower on each magazine. Follower. Make sure they all present the bullet at the same angle to the chamber.

Make sure the chamber of the barrel is scrubbed.

Make sure you use a light lube.

Try hand cycling the 10-round magazine at the range. Any hang-ups?

Both CCI MM and Aguila are fast rounds. In my experience, they will cause the slide to reciprocate too fast.

Try using CCI standard velocity 40 grain.

Tha is for the tips!!

From the Sig Sauer .22LR conversion kit manual:

“We recommend using Hi-Velocity .22LR ammunition with this Conversion Kit. While this kit will perform well with the majority of commercially available Hi-Velocity ammunition, not all brands
will function as well as others. Try different brands until you find a selection that provides a level of performance you are satisfied with. Using standard velocity ammunition will cause erratic or inconsistent function of the Conversion Kit.“

From some guys on another Sig site:

“I have the .22 kit on a P226, and with good ammo (CCI Mini Mag) it runs quite well”

“ I have the .22 kit for my P226. It doesn't like Federal Auto-Match or Aguilar Super Extra verymuch, but it loves CCI Blazer. I get a lot of FTE's with Federal. So, I buy CCI Blazer in bulk”