CB
posted this
06 February 2010
IM not so HO I believe Ric is right on. I would go a bit further and say that evidence is lacking to show that a small case capacity compared to bore size is necessary for match winning accuracy.
It makes some sense to to have a modest case capacity for the bore size. The top heavy and UNR shooters usually shoot something like the 30BR instead of 300 Win. mags. It saves some powder for a given bullet and velocity. That in turn saves money (always on the mind of cast bullet shooters) and also reduces recoil a tiny bit since a little less weight is shooting out the muzzle.
But the best production shooters (almost all shooting 308's with a lot more case capacity) do almost as well as the heavy and unrestricted shooters while shooting production guns as opposed to $3,000 custom benchrest rigs. This casts doubt on the assumption that 30 BR is much superior. I wish somebody that knows how to shoot would build and shoot a full race 308 to test the theory. A 300 mag would be even more interesting.
Wait -- Mike Mohler has already run this test, with a production class rifle. But the lesson has apparently been ignored.
Perhaps the best evidence that large case capacity isn't too much of a handicap is Mike's record, with the 243 win, of almost always beating 90% of the 308s and often beating them all (he won all the marbles at the 2007 nationals and owns several national records).
Mike's performance with the 243 also calls into question the assumption that a competitive cast bullet gun has to be 30 caliber but nobody seems to have noticed that either.
We do seem to have a bit of the herd instinct in us.
John