Re: .300 win mag brass?
I shoot a 300 Win. Mag alot, and I have been using Winchester brass and a old Pacific full length sizing die. I do not weight cases, I just deburr the flash hole, trim every time, and polish the inside neck with steel wool. I size only down to the shoulder, but do not touch the shoulder as to headspace on the shoulder. I am able to maintain 1.5" and some times better at 300 yards. Am able to keep 5 shots at 1000 around 10", but only did 14.5, 10 shots at a 1000 benchrest match.I can get 15 reloads per batch of brass, no chambering problems. The necks start spliting about then, so I toss that batch and start on another. I suppose if I weighted, sorted, etc., like you are doing, I would see better results. But I guess I am lazy, and not very competitive. My friend is heavy into 1000 yd benchrest and uses a 300 Win. Mag..His choice is Federal brass and he is getting pretty good results with no problem. Hold on to your hat, as I am sure more information is on the way from people who are more experienced with this subject, and good luck with your shooting project!