Brass sorting question

[handirifle]

Boy this thing is sprouting roots. I do a lot of stuff to my brass, first time, that a lot call useless, but even if it's in my head, they seem to work.

I have not worked up a load for this rifle since the 70's, but when I did, I was getting 100yd clover leafs with the Sierra 85gr BTHP Gameking bullet (243). Something was working. Thanks for the feedback and opinions. For the record, in the past I never weighed any brass before, so this is a test. This time it is with the Barnes 80gr TTSX, mainly because it is one of the few choices I have to hunt with, here in Kalifornia.

[hardnosestreetcop]

Cartridges cases can vary considerably from manufacturer to manufacturer. The composition of the metal frequently will differ, the overall length often varies even in new cases from the same manufacturer,and certainly the internal capacity will often be different. Because of these variations you should never mix the case brands, and it is always advisable to not mix case lots. Minor differences like these can vary case capacity, that can translate into variations in pressure and how the loads performs.

[bigedp51]

The smaller the case capacity the more it will effect chamber pressure, meaning larger magnum cases will be less effected by case volume.

Below the older lot of Lapua .223 brass with 28.0 grains of H2O case capacity will have *6,000 psi increase in chamber pressure over the Lake City case with 30.6 case capacity.
(*Quickload defaults to 28.0 H2O case capacity and your "fired" cases must be checked for H2O capacity)


As you can see below there is a reason why people buy Lapua brass and that is because of its uniformity in weight and volume.
(see extreme spread below in case weight variations)




handirifle

I buy a lot of once fired Lake City brass in 5.56 and 7.62 and I form my .243 brass from 7.62 cases and then sort by weight. The 7.62mm, NATO, Ball, Special, M118LR cases are just weight sorted M80 cases and must fall into a 2 grain weight variation range limit. And I also use weight sorted M80 7.62 Lake City cases for my Savage Hog Hunter .308. If this is good enough for military match grade and sniper ammunition its good enough for a old fart who drinks too much coffee and has chronologically gifted eyesight.