I agree - possible, but not cost effective to alter a magnum bolt and make a .270 out of it. It's actually not cost effective to rebarrel it either - even if the bolt face was the right size. Just sell it and buy a comparable .270.

Having said that, Stubblejumper has hit the nail here. Put on a Simm's Limbsaver recoil pad. Down load the 7 Mag to .280 Remington levels - or buy the Remington 140 grain managed reoil factory loads. I am currently loading a 7 Mag to 7MM-08 performance levels for my 13 year old son. It is extremely pleasant to shoot.