I'd have to check to be certain but I believe the PPC and other short rounds wouldn't clean up the 243 chamber. The standard 6mmRem will also not clean up the chamber leaving an ugly knot in the new chamber where the 243 shoulder is located. The AI (ackley Improved) version would however likely work OK but would not remove enough of the throat to fix a problem there. A 240 weatherby or 6mm-06 would however take care of the problem. There are several others that come to mind and a purchase of 'The Cartridges of the World' book would add more. The 244 Apex is a monster as is the 240 H&H. Unsure of the names here but you get the drift.. Of course you understand that there will be several changes neede in the savage rifle to alter for some of these round..bolt head, bolt stop, mag box,, etc..