My 7s not only have the right twist even for light bullets, they seem to not be as accurate with the heavies. I'm talking 1.5 MOA vs. bugeyes that I was used to with other rifles. But I do not shoot as well as when I was young so it could be me. Also the commercial Mauser from 1936 has shorter barrel and shoots 3/4 MOA and with most ammo...so we will see if any particular handloads improve either gun. If the longer one does not shoot, no matter, I have other barrels to put on it. Good point on the bullet volume though.