I have a later model Ruger #1B in .243 and would like to find out if I can do a simple rebore to 6.5x55. I don't want to rebarrel or make it a big project, just keep the original barrel the way it is. Im happy enough with the .243, just think a 6.5x55 1B would be the cats a$$. If it can be done, who would be good to do it? Thanks 021

One possible problem would be whether the 6.5x55 chamber would clean up the shoulder of the .243 chamber.

I've used Classic Barrel and Gun Works (www.cutrifle.com) for several rebores, with excellent results. You might want to talk to them.

Thanks, I'll give them a call.

Don't go into the 260 briar patch, which would clean up a 243 chamber without barrel setback, feed identical to the 243, and give the same or better performance than a 6.5x55.

and, it's on...

Will a reboring service do a rebore for that amount of bore difference? I was under the impression from others I've talked to and on this forum that the minimum that most rebore outfits won't do a rebore under 2 calibers difference in order to clean up the original bore completely.

Bob

That only applies in some instances. For instance, one cannot take a 25 caliber barrel to 6.5mm since the nominal bore diameter of a 6.5mm is smaller than the groove diameter of the .25 (256 vs 257+). Another case would be the 270 to 7mm.
Someyimes, if a throat is badly burnt out, the surface won't ream well and it is difficult to get a good finish in that portion of the bore so one might have to go up another size.
The 6.5x55 will not clean up the 243 chamber. One would have to go with a 65x55 AI. As mentioned, the 260 would work perfectly and there would not be enough difference in performance to mention. GD

Greydog, How about .243 to .257?

I don't think the 6.5X55 will work because the body of the 6.5X55 tapers more steeply than the .243.

If you're not averse to wildcats, I'd look at one based on the 444 case as IMHO single shots and rimmed cases just go together.