Jimbo444-
Don't worry if your 444 has the slower 1-38" twist. It will work just fine with bullets up to 300 grains, and maybe even a bit heavier, depending on bullet design. All you have to do is make sure the bullet is spinning at a high enough rpm to be stable, which means the bullet must have enough velocity. 300 grain bullets will fly true and penetrate straight as long as you start them at about 1900 fps or faster. This is easily and safely done, and the heavier factory loads are all fast enough to be stable in the 38" twist barrels. My own 444 is very accurate with heavy bullets, 300 grains and up, and it even shoots cast bullets well, despite having 1-38" micro-groove. This is not unique to my rifle, as many long-time fans of the 444 can tell you.