A couple of generations ago, before there was a chronograph lurking under every loading bench, gun makers used barrels of sensible lengths. If you got a .30/06 or a .270, most likely you got a 22-inch barrel. If you bought a magnum, it was probably 24 inches. Over the years, however, barrels have been getting longer, possibly because manufacturers are afraid their guns/ammo won’t deliver advertised velocities.
I’ve never feared shorter barrels. They are handier to use, weigh less, and often are more accurate than the longer ones. And as a rule, you lose very little velocity when you lop off some steel.
As proof of this, ace Texas rifle maker Charley Sisk recently published an experiment where he barreled six rifles with 27-inch tubes and chronographed them, cutting each one back an inch at a time. Space doesn’t allow me to list all the figures, but I can give you the totals.
– .22/250, 27 to 24 inches, from 3, 469 to 3,407 fps
– .270 Winchester, 27 to 21 inches, from 3,115 to 3001 fps
– .300 Win Mag, 27 to 22 inches, from 3,055 to 2,960 fps
– .340 Weatherby, 27 to 22 inches, 2,834 to 2,755 fps
– .338 Win Mag, 27 to 20 inches, 2,806 to 2,656 fps
– .257 Roberts, 27 to 20 inches, 2,860 to 2,717 fps
There are a fair number of variables involved, mostly involving bullet weight and the burning rate of your powder, but this tallies very closely with what I’ve seen. A few years ago, I had the barrel of my .338 RUM chopped from 26 inches to 24. Accuracy increased to an astounding degree, and velocity loss, with 250-grain bullets, was something like 38 fps.
But there’s a down side to all this. A .338 Win Mag with a 20-inch barrel is going to leave your ears hanging in shreds. A .340 Weatherby with a 22-inch tube is a .338 Win Mag that wastes a lot of powder. Some cartridges legitimately require 24 inches, and a very few really do need 26 inches. You have to use some common sense.