Interesting MagMan. That's one fast twist barrel for sure. Maybe those Wildcat 200RBTs would hold up......? Linksmechanic is right - no probs with a 9.5" twist. Mine's a 9". I've seen jacket separation with a couple different 22-250 Ackleys >>>>>>>>>>>>>>> POOOOOOOOOOFFFF !!!
I had actually looked at the 180 Bergers as soon as the 300 RUM came out. I thought, WOW, something able to push a .750BC bullet at well over 3,000 fps. I did some talking to some helpful folks, like Walt Berger, Jimmie Knox, and Bob Cauterucio, and learned more about jackets and RPMs. Walt laid the phone down for several minutes, walked upstairs, and retrieved some data on 6.5 RPMs. He concluded that the 180s were very iffy at the RPMs I expected from what was then a wildcat (the 7mmRUM hadn't been introduced) since the quality, but thin, Berger jackets might separate from the cores. Obermeyer reportedly found out the hard way in experimentation. Being the gentlman he is, Walt suggested I talk to Jimmie & Bob ... also both fine people! The 156 and 176 Cauterucios have been my go-to bullets ever since.