I have a Yonkers Kimber .22 Hunter with feed problems with 3 of 4 magazines. I looked at all 3 - feed lips, ramp, polish - compared to the 4th and see no difference. The mis-feed seems to be the 4th round maybe a little high but sometimes the 3rd - no pattern.
Initially I used RWS subsonics which worked great and found that truncated rounds seem to be more of the offenders compared to a regular round nose lead. Now the RWS will occasionally misfeed. This rifle needs a positive, snappy bolt action - no slow movement - to eject a shot round. I have looked at the throat for maybe a ding or rough entrance to the chamber and it looks clean
A few years back, I sent the mags to Kimber, they sent them back with no real explanation and I accepted that this rifle/magazine is ammo particular. I recall a comment that the stated ammo quality/dimensions were not always consistent and this was a common element in mis-feeds.
Does anyone else have the same issue?, any fix?, is it just a pick-the-right-ammo-and-get-a-lot-of-it thing?