Boy, that's a tough one to answer, best in what exactly, ignition, functionality or accuracy? To further complicate things is the .22lr firearm itself, they can be rather picky about what they like to work with and be accurate with. I had a real problem with the Remington Goldens a few years ago that resulted in my giving away the remaining brick and a half of it, that was in revolvers, semi auto handguns and semi auto and bolt rifles. For a overall .22lr ammo for some reason I have good luck with Winchester X-Pert and Federal Champion as runner up. I almost got rid of a M-18 dash three that refused to be accurate with any ammo tried, and I tried a lot, finally I fed it some Winchester X-Pert and it shoots it like a champ. The best I could say is to get a mess of different brands of ammo and see what works best for you and your firearms. I know these days getting the stuff is not easy, good luck and good shooting!