The 338 275 speer had no flaws. It was and is as Elmer described. I started them at 2550 from my 338 wm and it killed elk like the hammer of Thor from close to far, 425, the same way. I think with some use of newer powders you could get a 338-06 near that level.
Actually, even Elmer didn't like the 275 in it's later years, sometimes lamenting how it had changed from "the old, heavy jacket version." He mentioned this more than once in his published writing.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
