MM, he is shooting a handgun off a backpack with a pillow in it...He's gonna get fliers!! I'm actually pretty impressed he is only getting one a session! That aint a rock steady rest!

TN, if you really want to test the firearm for best loads and grouping, get a much more solid rest, find what the firearm likes to eat the best, THEN start shooting with what you might use in the field. Caldwell has some pretty decent solid rests purpose made just for this and they aren't really expensive at all. I would suggest getting one for load development so you can get the absolute best results from your load workups. This way, if you screw up and miss one day in the field, you will know it is you needing more work at the range and not blame the load or firearm