I have a rifle chambered for a .888" .45ACP case. I trim .460R brass down to .888" and load up special rifle only rounds for it. So far with Longshot in doses a good whack higher than 12gn I've gotten 2000+ fps with 230's. With real rowland brass it works great. With .45ACP brass the primers fall out.
NOTE: NEVER attempt to duplicate my loads. Also never attempt to use anything like them in a handgun or semi-auto rifle. I'm way off the book. These loads will grenade a pistol and my rifle is a bolt action.