I looked around and didn't come across any sizable studies comparing brass brands and accuracy. I can find quite a few videos on do comparing brass for things like case length, case weight, case volume and the SD and ES for those measurements, but they never end with an actual accuracy test. The general assumption is more consistent means better accuracy but just wondering if there are tests supporting this. In the last year or two, though, it seems like several reloading/accuracy assumptions have been tested and found to maybe be inconclusive at best. Seems like several good shooters have recently detailed pretty simplistic reloading habits:
The both are generally hitting the "easy button" with components but interested in seeing the evidence that lead to those conclusions on brass brands.
In both those videos, the one thing both emphasized was using "quality components". Though they didn't really say what "quality components" means, I assume they're referring to the consistency within a lot. You don't want to mix lot or various head stamps. This is where Lapua shines as well as a few others. If you've got consistent brass, it goes a long ways in producing good results. In this day and age, technology has made it possible for just about any brass manufacturer to do that (like what technology has done for fit and finish of automobiles). There was a time, a few decades ago, that brass was not so consistent and that's pretty much when a lot of these things reloaders do today to improve the brass originated from.
Several years ago, when I first started precision reloading, the same question bugged me as I couldn't find real testing data that showed what kind of difference might be found on target between different brands of brass. I collected a bunch of various branded once fired range brass and set out to see how much difference there might be. I measured everything, and I mean everything like case weights, case volumes, pocket depths, neck thicknesses and their variances, case lengths, flash holes, interior burrs on flash holes, etc., etc. What I did to precision prep them was to uniform them in every way that I could and compare my results on paper and chronograph. In comparing those that were precision prepped with those that were not and of the same head stamp (e.g. Federal, PMC, PPU, Perfecta and Remington) the precision prepped brass performed better than those that were not, both for what I'd get on paper as well as more consistent velocities. But in comparing the different brands that had been precision prepped, I couldn't find any significant difference. With the higher quality brass, like Lapua and Peterson, that was not so extensively prepped, I didn't see any significant difference between them and those others that were extensively prepped.
While I can get those other brands of range brass to shoot really well, it's too much work and I find it better just to go with high quality brass, as they tend to be pretty uniform within a lot. But, there can be differences from lot to lot in case volume, which can lead to having to make adjustments of powder load to maintain the desired performance.
For differences from lot to lot, if you haven't see what I've posted in other threads, here's that Peterson Cartridge Co. Ballistician Testing Data sheet:
