Measuring .22LR Ammuntion

[horseman2]

Federal Target and HV Target are manufactured in the USA.
Federal Match 922A is manufactured by RWS to R50 standards.
Rim thickness is very consistent and can be split into two groups of high and low. A reading of 0.041 would have one group of + and one of -.
Eley is similar.
Chilly807 has made a fair assessment of Federal target and the three groups he separated. I did something similar with CCI SV to test in a Ruger 10/22 just for $hit$ & Giggles but the wind factor made the test inconclusive so it was essentially a function test.

 

[Chilly807]

Federal Target and HV Target are manufactured in the USA.
Federal Match 922A is manufactured by RWS to R50 standards.

Thanks Mel, that's the link I was missing. I was under the mistaken impression that the Federal Target I tested was the Gold Medal Match ammo. I was thinking it was pretty economically priced.. I should have known better!
Having said that, it shot decently in my 452. I'm starting to think that rifle prefers slightly faster ammo. Both CCI SV and the Federal Target shot well in some recent shooting sessions. One is listed as 1070 fps, the other at 1080 fps.
I need to get something with more consistent manufacture and the same speed.
I've never tried the SK and Eley high velocity offerings. I'd like to find something that's just under supersonic with good quality control.

 

[grauhanen]

Rim thickness is very consistent and can be split into two groups of high and low. A reading of 0.041 would have one group of + and one of -.
Eley is similar.

It's not clear what the second sentence means. With regard to the first sentence about rim thickness consistency, there are reports that rotating the round can give as much as .001" difference. Furthermore, the case head (the bottom of the cartridge) is not always flat. It may be bowed up or even dish shaped. Some methods of measuring rim thickness may only account for the largest measurement.

In any case, I don't plan to measure rim thickness. There are too many reports from experienced shooters who have tried it only to abandon it as not worth the effort. I think I'd sooner use better quality ammo for which there is a consensus that there is much less rim thickness variablilty.