I reccently was given a new unfired stainless 338RUM barrel with muzzle break. I was told it was a takeoff XCR barrel and it looks like it to me. I acquired it as part of a deal with a custom 300RUM and this barrel can be switched on the same action and such. Needs a gunsmith to do it so I see little to no advantage there. I am thinking I might want to make a new gun out of it but don't want to get over $1000 into this build if I can avoid it. Basic questions would be what is the most economical way to proceed with a 700 action and which one? Would a normal long action work with this caliber? Would actions other than Rem work with a new build and this takeoff barrel?
What would you do for those that have more experience in this than me.

Buy a cheap 375 Remington SPS, change the barrel and put a nice Boyds laminate on it, you will have money to spare.

Reg S&F

Would any 700 magnum action work for the 338 RUM? I have a complete 700XCR in 375 already that I don't want to take apart. Almost seems senseless to buy an SPS to take apart to basically build the same thing in the 338RUM when you could just buy a complete SPS in the caliber already, strip the stock to put a better one on there, bed it and trigger job and have the same thing. What am I missing?

Use, long action Rem 700 will fit a RUM.

I agree with the other, do a 375. Unless you want a long range thumper, then keep it as a 338 RUM.