Ummm Denton
I do believe that you ment that the smaller chamber will produce HIGHER pressures & velocities than a typical barrel.
Hawk
I've seen 270fps difference with the same lot of ammo, by simply changing the throat (and it cost me an inch of barrel to get rid of the slophole that was in their). Typical chamber with oversize throat, 2725 average, match chamber and minimum diameter throating, 2998 (Nosler has reported the same loading at 2995 to 3007 depending on issue # of the manual).
