The real answer as to whether your previous loads will shoot the same in the .300 WM Long brass is going to be likely a function of the .300 WM long case volume measured in gr. H20 vs. what ever brass you are using currently for that load.
So if its Peterson regular .300 WM brass vs. the new long, I would say measure the two cases on volume of water say 3-5 cases of both and just see what each brass weighs, dry and filled, and get a sense of case volume differences. I will be doing this myself since I have both types of Peterson Brass, Just need to get it once fired on the new stuff and run the measurements. Haven't had a chance yet, but maybe someone else can attest to any differences noted on case volumes of the new long version of Peterson.
So if its Peterson regular .300 WM brass vs. the new long, I would say measure the two cases on volume of water say 3-5 cases of both and just see what each brass weighs, dry and filled, and get a sense of case volume differences. I will be doing this myself since I have both types of Peterson Brass, Just need to get it once fired on the new stuff and run the measurements. Haven't had a chance yet, but maybe someone else can attest to any differences noted on case volumes of the new long version of Peterson.
