According to Hawks, the 30-378 recoils more than twice as hard as a 300 ultra mag.

http://www.chuckhawks.com/recoil_table.htm

I'm sure that 400 bucks each for these is a good bargain. The caliber is faster than anything else when it comes to pushing bullets.

If they're NIB or close to it, just buy 'em.

And then go clear some timber on the back 40 with them.