Heck I'll do the lathe work for you. Dave Kiff at pacific Precision is the guy to talk to on the reamer, he is fast, good, and wildcats don't cost extra. his standard reamer runs $135.00 but that comes with a live changeable pilot.
The first thing I would do when fitting a bbl to a savage is throw away the bbl nut, it is not needed or wanted by a man that knows how to run a reamer, if you do it right you can get headspace to the .001"
we do not need a headspace gauge, we can use a ctg. case for one...I prefer to fit them snug to the brass then surface grind .002 off a shellholder to bump the shoulder.
I also have a fine 308 bbl gathering dust here, it came with a 700 rem action I bought, it is 20" or so long, stainless steel, unknown maker but nicely button rifled, and about the same contour as a remington varmint special, it is 1-12 or 1-14 twist.....it is a real nice bbl and would have plenty of shank to fit to your rifle. $50.00 for the bbl and to fit and chamber it is all I would want. This bbl belonged to VirgiL King the Houston Warehouse researcher of benchrest fame...he had it setup for a hunter BR rifle. I ended up with the 700 action and it is now a 22-250AI.
and I know MROliver77 would go in with you on the purchase price of a 30 caliber reamer, he is wanting to do a custom cast boolit bbl for his New England single shot. You guys both have the same general idea of a ctg. in mind. and you both want a throat for cast bullets.
Bill