Before I start, one caveat: <img src="/ubbthreads/images/graemlins/ooo.gif" alt="" /> these won't be the same from a pistol, as a rifle.
I recently bought a new CZ LR rimfire, due to all the good things I've heard. I sure havent been disappointed! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> After scoping, I began to gather up all the different types/brands of ammo I could find, and began break-in, chronographing, and accuracy testing.
This rifle's chamber won't accept Stingers, so they weren't tested. I tried everything I was likely to use. A few types were excluded due to price. I ain't gonna spend $5 plus on a 50-round box of .22s. BTW, it has a 22" barrel.
Some shot well, some less so, and some were exceptional. The biggest surprise was CCI's Quick-Shock. Hyper-velocity ammo, like Velocitors, ran in the 1200-1300fps range, maybe a tad more. The Quick-Shock ran better than 1750fps! Those things are like greased lightening! They are also scored inside the hollow-point, and supposed to fragment on impact. Note: a subsequent brick is only doing 1675-1700fps, so things do vary.
I was a bit concerned about penetration on larger varmints. So, when I had a deer hung up for skinning, I took a 25yd shot through the neck, just below the head. I was surprised to get full penetration of the neck vertebra, finding shrapnel under the hide, on the off side. Now no piece found was over maybe 5-10 grains, but the fact that they penetrated the neck musculature and the vertebra at all, reassured me enough.
While they aren't the most accurate round in my rifle, their 1 1/2"- 2" groups at 100yd are good enough. And they pack enough when they get there. I'm sighted about 0.6" low at 25, and dead on at 50, and again at about 75. The 100yd impact is only about 1" to 1 1/4" low. I can live with that.
Sorry for being so long-winded. You can see the chrono data, and groups at:
.22 Group/Velocity Testing I made no effort to "condition" the barrel to each ammo type. I just fired a group, then went on to the next. I think it would be time well spent for every rimfire shooter. It's the first time I did something like this with a rimfire, and I learned a lot!