According to my Speer #13, with 40grn bullets and H335, 28.5 is listed as max load (and also is listed as a compressed load) with a velocity of 3133fps. I don't know how you could figure that an extra 4" of barrel and 1.5 grains of powder would get an extra 1000fps. Anyway, if you wanted something that fast or faster you need to look at .22-250, .220 swift, or .223wssm. Don't over do it, I've loaded for guns that show pressure signs before you hit the "max" loads. And remember that the weakest link in the chain is not the rifle, but the casing.