I may hate myself for wading in here, but here goes...
My Dad aquired a rem 700, 300 win mag with a shot out throat and some ports cut in the end of the, I believe, 24" barrel. To save the rifle, he had the chamber cut to 300rum. After finally getting it to feed and eject (we're a little slow on the learning curve), and shooting it some, it seems fine to me, though no chrony info.
Shooting that rifle convinced me the 375 rum wouldn't be that bad recoil wise...seems close to my 300wm for kick (I toldja we're a little slow on the uptake, didn't I?). It's been a coupla years since I fired it, but I don't recall any fireballs, nor did we set off any car alarms or seismic events. I always shoot with double protection at the range anyway.
A cheap way to try it might be getting a 300wm takeoff and rechamber it (feeding issues aside). Or you could just cut off a factory rifle, and then retube with a quality barrel when yer done testing. Wadda ya got to loose? If you don't like it, yank it and build a 300 rsm...
John
