When they first came out, I had excellent results with the .50-295-grain lead "Black Belt" in my 1/72" twist Hawken. My powder charge was 120 grains of Pyrodex RS, and accuracy was good at 100 yards.

I recently shot some of the new copper-plated 295-grain Power Belts with the same powder charge in the same gun, and the results were horrible! I think maybe the plastic wad is not coming off these new ones like it used to do??? What other causes could spoil accuracy in a gun that used to shoot them so well? This rifle is still extremely accurate with both RB's and 370-grain Maxi Balls! So I don't think it's the gun!