[Rapier]

Old steel mover here, there are several 6.5mm cartridges specificly developed for the handgun. The 6.5 TCU is at the very bottom of the power scale but is accurate. The 6.5 BR has the same capacity as the 6.5 TCU (35-36 gr) as does the 7mm versions of each cartridge. Odd, but true. Now upping the scale a bit you come to the 6.5 IHMSA which is a 300 savage based cartridge of 47 gr designed for handguns (your 250 answer) but dies may be a problem and then a cartridge specificly designed for the TC, the 6.5 JDJ, based on the 225 Win 45gr (all stuff available from JD Jones) also an excellent choice for the Encore. I have owned most of the chamberings over the years and all are excellent performers. However, I have two favorites, the 6.5 BR and the 260. The BR is extreamly accurate but limited in capacity for hunting. The 260 at 55gr is also extreamly accurate, a factory round, and can be loaded down or up to give you all you want in velocity, accuracy and yep, muzzle blast. Just stick with the 14 inch barrel in a 260. If you need a 10 inch, go to the BR or JDJ.

If you do a BR, you can make your own dies by using bushing insert dies and starting with the 7mm body, just switch the expander to a .264 and figure the sizing bushing as normal. Buy 6mm BR brass, expand the neck and fire form. It is a very simple round to make.
Best of luck.
Ed

PS if you need load data I still have mine for the 260 and the BR, both were XPs. If you want a package deal give JD Jones a call, he answers the phone at SSK.