What is you main goal?? the 22-250 in a factory load can be very hot like 60,000 PSI or more. however with that said it is a awsome round for long range varmints. it is a barrel burner so its not some thing you want to shot 1000.s of rounds through rapid fire. unless you want to reload the 22-250 to a lighter load Id be hesitant to use a standard AK bolt. I have plans to do a 22-250 on a standrd AK bolt with a m70 trunion but Im going with a fast twist barrel and plan on loading it light. The idea is to get more than 223 speeds with a 80+ grain bullet and over come the loaded length issues you have a AK/AR length mag well And by loading it light hope to avoid some of the barrel burning issues that a hot fast twist 22-250 have. i alkso have a 22 cheetah reamer that is a 308 necked down for really cooking barrels fast LOl. Im shooting for a litttel mre than 223 can offer with a heavy bullet.
The 260 down loaded is a good choice. as is any other 308 win based round. If your hunting they allow heavier bullets and more power wiht faster speeds. if your shooting paper or plinking then a grendal might be a simpler build and cheaper IF there is everry any cheap wolf steel ammo. 7.62 brass can be used to make 260.
another choice that is a good idea is a 243 win its between a 260 and a 22-250 it will shoot 58 grain bullets at around 3800 fps and 100 grain or heavier at around 2800 Fps it will work on varmints to deer. bras and ammo is everywere. the 115 bullets will rival some of the 6.5 offerings for BC. Im currently working on a light weight 243 for a youth hunting rifle. it uses a standard AK Bolt and trunion ( bolt opened up) Ill load it to the light side of the book. If your shooting under 500 yards a 243 will likel
if you planing on using factory ammo in a 22-250 ID recomed you start with a 308 Sagia it should handel it. just keep in mind 22-250 is really hot it likely the hottest non magnum rifle round out there.
The main benefit of the 260 over the 243 and 308 is the higher BC of the long heavy bullets it will give you more at longer ranges. Im nbot sure you will be shooting a AK in any calibure at over 500 yards but if you are then its a good choice.
also dont forget there 6.5 creedmore it has a lower chamber pressure is said to be more effeciant than the 260 and allows the bullet to be fully seatd out in a 308 length mag or action. hornady makes reasonably priced brass and I think it can be formed from 308 brass as well ( dont quote me) it is gaining in popularity with the ar 10 crowd aswell as target shooters with bolt actions. It might be a better choice than the 260 remington especaily down the road. factory ammo is avaliable from hornady also and possably others.
IF THRE WERE 3 LUG BOLTS AND TRUNIONS AVALAIBLE THIS WOULD BE A LOT MORE FUN AND COST EFFECTIVE.