Thanks for all the replies.
OK. I guess I need to explain my dilemma in a little more depth.
I've been using my rifles to shoot some ORA and DCRA precision matches (out to 800 meters.) I may want to do F class later on. Obviously, I want all the accuracy I can squeeze out of my rifle and wallet - but I'm known to be a cheapskate when it comes to competition equipment

Just ask Hungry.
I presently have a Winchester model 70 short action bedded into a HS precision varmint stock and equipped with a very old target barrel that is somewhat light for target barrels and was designed to shoot IVI. I used this rifle once to tie for 3rd place in the sniper matches at CFSAC about 10+ years ago. Its sometimes still capable of some one-ragged-hole groups at 100 yards, and the throat looks ok but the scores in competition aren't keeping up anymore. The fact that I can no longer get much practice to learn the wind doesn't help when using a .308
I also have a Savage single shot .223 bedded into a heavy laminate target style stock. It is fun to shoot pennies at 100 yards, but in competition, I've found the .223 is all over the place in the wind and my spotter is unable to see the swirl or the splash (OK he can't see it on the .308 either...

). I really like the ergonomics of the stock and the location of the safety on the tang of action.
I've decided that I'm going to get a 6.5x284 in order to keep up with the arms race.
Basically, I have the option of:
1. Rebarreling the Savage to 6.5 and getting a new bolt head for it. It shoots well in present configuration, but I think rebarreling and getting a different bolt head would change some things that may necessitate action truing. The Winchester can be kept for short range matches or matches that need a magazine.
2. Rebarreling the short action Winchester to 6.5, thereby making the magazine pretty much useless as well as wasting a barrel that may still have some life. The Savage would gather dust as a Safe Queen.
3. The more expensive option: Getting another Winchester or Remington in a long action to build upon.
The Winchester can be kept for short range matches or matches that need a magazine and the Savage would gather dust as a Safe Queen.
Any further advice or suggestions would be appreciated.