The gunsmith is working on this now, and it will be back in a week or so. It is simply a 22/250 necked to 6mm, with no other changes, so it isn't quite a 6mm International.
Barrel has a 1:10 twist, and we want to use bullets in the 65-75gr range. Anyone out there using one of these, who would like to toss in their load recipes? Just looking for starting points and ideas.

John,
I've been shooting a 6mm-250 Savage since about 1990. I had Douglas Barrels do mine with one of their SS Airguage barrel in a heavy varmit 24" long 1-in-12 twist on a Remington 600 action, I only live one hours drive from Douglas. Please reduce the following loads 10% and work up, these loads are max in my barrel. I used Federal large rifle bench rest primers with all loads, and Remington 250 Savage brass.

65 Berger,H-322,36grains-3500fps,shoots less
than 1/2MOA,
Best load
70 Nosler flat base,IMR-4895,37grains-3470fps
70 Nosler,IMR-4320,38grains-3450fps
75 Hornady HP,H-414,40grains-3300fps
My 1-in-12 twist barrel doesn't seem to like bullets heavier than 70 grains. The 75 Hornady shoots around 1" and all the rest shoots less than 1". I hope this helps some.
Albert

Thanks Albert. This rifle is my wife's and I would prefer not to blow her up, so you can be assured I'll work up to everything.

She's decided she would like something different to the 243, but with enough urge to go to 500 metres, and good accuracy. From your numbers this cartridge would seem to fit the bill nicely.

It's a rebarrel on her current 243. Rem 700 BDL action, HS Precision stock, #5 Maddco stainless barrel, and Leupold VXIII 6.5-20*40. Action is also being trued whilst it's in pieces.