I've owned a couple of K-22's that would stick on the first 6 rounds, a couple more that would get sticky after 60 rounds or so, and still others that were extremely finicky about ammo. But I also have an old 1948 K-22 that will still function smoothly after 200+ rounds, and digest any and every brand of ammo I feed it with nary a hiccup. I can't explain it, it's just the nature of the beast. When I find a good one I usually keep it...