I had a 6.5/284 built on purpose in a Remington SA , back in late 90s ( I never intended to shoot more than 120-125gr) I necked down the Winchester 284 brass. It was a flat out wind deying, flat shooting killer of deer/antelope/exotics, especially with the Nosler 120 BT. The 125PT was tough enough I'd use it on elk, though I never did. But I'm not a LR Hunter either, and all my kills were under 320yds. Later on, I tried my safe loads I was using in the WW brass in the "new" Hornady, Norma, Lapua brass and I couldn't get the same speed w/o loosening the primer pockets. But even a bit slower, it was still a great killer. BUT, in that PF SA the last round (or only even) would fly out of the rifle when feeding. It drove me bonkers so I traded it to a guy who didn't care.