p-man
Gold $$ Contributor
I think one needs to look at the desired endstate. If you're a competitive and/or long-range shooter, the odds are you will have a somewhat robust barrel that tolerates heat much better than ultra-thin and light-weight sporter contour hunting barrels - additionally, most hunters - excluding varmint guys - shoot from a cold barrel. So for them the best but most practical measure of accuracy is one predicated on the conditions of the hunt. How many hunters ever shoot more than 2, maybe 3 shots at their game animal; even if needed, how many actually have an opportunity to take a 4th or 5th shot? Not many. So for them what makes sense when punching paper is groups of no more than 3-shot. For instance, I have a Model 96 Mauser that was fully converted to cock-on-open and with the original barrel (never issued) turned down to what could best be considered a Win M70 featherweight contour. It is what is now a 40-year old piece of walnut inletted & glass bedded well with the barrel transition and taper free-floated. The point here is to point out that this is not a garage-job mil surplus hackjob. Currently it has Docter 3-9 glass. It has a twist of app 7.5 and at a 100-yards, shoots just about anything over 140 grains 2-shots touching out of cold barrel, the 3rd will be about 3/4" out, the 4th about an inch beyond that and so on. Chasing 5-shot groups would make no sense and in reality the only thing that really matters isn't the measure of the 2-shot group, but that it hits exactly at the point of aim. With the apparent new rage for ultra-light rifles, for them seeking anything more than 3-shot groups from cold to mildly warm barrels is simply a crap shoot. Pencil thin barrels simply heat up quicker and their point of aim migrates more - and more quickly - than heavier contoured barrels.