.308 brass capacity

[michiganmike]

SWIFT MATCH GRADE .308 WIN CARTRIDGE CASES: Midway USA had the aforementioned brass on sale and I bought a box of 100. I had been using FC head stamped military brass, which was working well for me. Having read that military brass had less internal capacity, I wanted a commercial brand.

To my surprise, the Swift brass has a slightly smaller average capacity than the FC head stamped military brass. The difference was not great. The FC brass held an average of 49.5 grains of IMR 4227. The Swift brass held an average of 48.7 grains of the same powder.

I did not vary my method of filling the cases. And both the Swift and the FC cases were filled until the powder over filled the mouth of the case. I them swept the excess with a straight edge.

Yes, I realize that water is typically used for these comparisons. Granting that, I had expected the Swift brass to hold more of the same powder than the military FC head stamped brass.

Any thoughts? Has anyone used this Swift brass?

[Yodogsandman]

I always considered FC brass as federal commercial brass.

Could the large difference in capacity due to one case being fired and the other new?

[lightman]

I've never really heard of Swift brass, but I have done comparisons between other 308 brass. Federal is pretty thin and usually does have more capacity than many other brands. If you really want to be exact you will measure it with something besides a really course powder. Lots of shooters use water but even that has lots of issues like surface tension and other things that are over my head. Something like alcohol would be more exact. If you really want match quality brass, look at Lapua, Norma of Lake City Match. Yeah, I know they are expensive and sometimes hard to find. Will be interested in how the Swift brass works out for you.
















If you really want good brass, look at Lapua, Norma or Lake City Match.