I've had decent reliability results with several ammunition choices, especially minimags (which seem to run in anything), federal 36-grain bulk hp, and remington's subsonic non-plated 38-grain HP load.
The gun I mostly used mine in had a 1:9 twist and it did okay, good enough for squirrels out to maybe 50 yards or so. The heavier the bullet, the better it 'should' like the faster twist. I always wished I could use the Aguila SSS load, since it's a 60-grainer and should like the same rifling as a 60 grain .223 bullet, or at least close to it. Never could get it to be reliable in any semiauto though.
If you get occasional failures to fire, check your firing pin. Never had this particular issue with my ciener, but once with the cmmg. My cmmg 22 upper started getting failures to fire, maybe one round out of five or six, and it took me a while to figure out that the firing pin was broken in just the right place that it was still held captive, but could rotate in the channel. Like most 22 firing pins it's more of a blade shape (like a flat-tip screwdriver) at the tip rather than a round shape like most centerfire firing pins, and when it was rotating freely inside the bolt, it would hit the round with enough force to ignite it, but turned in such a way that it missed the priming compound in the outer rim:
Once I found it and replaced the firing pin, all was good. But something to watch for if your gun acts like it's getting light strikes or bad ammo.