One easy way to play with that, Buzz, is to find some pvc, or other type plastic tubing that will just slide in the stock bolt hole, and leave it long as possible. Epoxy some shot into one end of it, just guess at the amount needed, to get started. You can then insert the tube into the stock hole with the shot at either end and try it with the weight forward, or rearward. You could even make one up with the shot midway the tube, or add more, until you get what you want.

May God bless America and those who defend her.