I think that these bullets that were originally meant for a pistol would 'scream' out of the barrel. 300gr HP at oh 2800-2900fps or so would absolutely destroy a woodchuck. Would these bullets hold up to the extreme forces of a rifle velocity?

Hmmmm, actually I have been thinking about those saboted .45 caliber pistol bullets (for black powder deer rifles) out of .510-.505 Gibbs. I'll be busy for another 6 months or a year working up loads for big bullets, so no doubt RAB will try that first, but I think it will be fun. I recall the A-Square manual has loads for pistol bullets out of .358 Norma Mag., and the author liked disintegrating rodents a bunch. While my Hornady and Hodgdon and Sierra manuals don't list loads like that, my old Speer #11 manual lists a .350 Remington Magnum load with the 125 gr. JHP pistol bullet at (heh, heh) 2857 fps. I think most of the jacketed pistol bullets will hold up well at moderate rifle velocities.

I shoot a 500 Linebaugh but I doubt the bullets would make it to the target at those velocities. However, we'll never know unless you try. If you do try be sure to let me know the results.

Well, I'm going to try the Hawk .510" 450gr first. We'll see what happens. Keep in mind that my rifle is still at the smith's being built.