Re: barrels: fewer grooves better???
I'm sold on that theory, My 300 winmag had a shilen bbl & lasted about 1500 rounds before the groups opened up to over 1 moa. I replaced it w/a 3 groove Pac-Nor & have put about 800 rounds through it. Measuring w/a stoney point comparator, I've seen the O.A.L. to rifling move .47" in about 800 rounds. When the shilen was replaced the O.A.L. of the rounds had to the rifling had increased by .167". None of this is scientific proof since I experimented w/alot of lightweight bullets w/the first barrel as well as various powders (H380 to H870 w/155 - 220MK's). The Pac-nor has only had 190 - 240MK's and powders faster than RL 22 have not been used. That may account for my barrel seeming to erode at a slower rate than the 1st barrel. Either way, I'm happy with it & will replace it w/another 3 land & groove barrel when the time comes.
Hope this helps,
Did I hit it?