BBT in escape

I have been shooting the 41 gr bbt with 250/252 band, lubed with bike wax. ave FPS is 866 and groups are less then 3/8 at 25 yards from support standing. When it hits a critter it knocks em a$$ over tea kettle. It did not shoot the 51 gr well though. It needs a firm push into chamber, I use the flat side of my pocket knife to push in place, it snaps into battery. Casts easy. Use soft lead. Might try a harder mix when weather breaks.