I don't know if they are actually "the best," but I have found CCI ammo to be consistantly good stuff.

By asking what is reliable as far as fail to fire I couldn't tell you the last time I had a missfire from a CCI product, all of it is really good stuff. I have to admit that I've never used any of the hyper velocity rounds. But if your asking for reliable feed and extraction, you'll never know until you try them out in your gun. Just like the saying "One mans junk is another man treasure". I've seen 2 guns of the same model have very different tastes in ammo.

Cleanest... Can't help you much there. To me, rimfire = dirty in a autoloader. I always clean up after every range session anyway so it matters very little to me.

I went out today and bought several different brands and types of rounds. I've always had good luck with CCI as well. I have been using stingers as a self-defense round in my wifes P22 and I broke it in with velocitors. A have had a few misfires and failure to cycle with Federals 550 pack but considering I only use the Federal during target practice, that's not really an issue. Ill post back after trying out a few different boxes of ammo.

Okay, I fired 100 rounds of each ammunition and cleaned the test firearm between each brand. I took notice of misfires, failures to feed (FTF), failures to cycle (FTC), amount of lead fouling inside the barrel (LF), and of course how dirty they made the pistol (DF). The firearm used in the test was a Walther P22. Lead fouling and dirtiness will be judged on a ten point scale with "1" being the worst and "10" being the best. The results were as follows.

CCI STINGER 0% misfire 1% FTF 0% FTC 10 LF 8 DF

CCI MINI MAG HP 0% misfire 0% FTF 0% FTC 10 LF 10 DF *WINNER*

CCI VELOCITOR 0% misfire 0% FTF 0% FTC 10 LF 8 DF

REMINGTON THUNDERBOLT 3% misfire 0% FTF 0% FTC 9 LF 5 DF

REMINGTON SUBSONIC 5% misfire 0% FTF 20% FTC 8 LF 5 DF

REMINGTON TARGET 1% misfire 0% FTF 0% FTC 9 LF 6 DF

FEDERAL 550 VALUE PACK 9% misfire 0% FTF 10% FTC 10 LF 5 DF

FEDERAL LIGHTNING 1% misfire 0% FTF 0% FTC 9 LF 5 DF

Rimfire is inherently dirty so take the DF values with a grain of salt. I came up with them by using the cleanest of the bunch and using it as the benchmark for what a "10" would be based on.

The brand that I see having the most problems on the range in .22LR is Remington Golden Bullet.