Heres the deal, I have a barrel that is threaded to fit a ruger action and chambered in .338 Jamison which is essentially a .338 WSM. I just picked up an old M77, tang safety model action for cheap! Would like to rechamber(myself) the barrel into a long action .338 chamber. It has a standard magnum bolt face. Initially I was thinking 33 Nosler but would like to get away from using Nosler brass, have not had good luck with their brass(blown pockets). I'm not against building my own brass but would like to know what all my options are if I'm going to do that. So are there any other options similar to the 33 nosler that may give better results in a standard magnum action?? I would like to push 250-265 grainers from the mag.