There's a much cheaper solution and it is simple too. You'll need a ziploc bag, lead or steel shot (Buy pellet gun BBs if you don't reload or know someone who does). Remove the butt plate from the stock, add shot to bag, place bag in stock, re-install butt plate, repeat until the weight is to your liking! Once it feels right your can wedge paper or plastic into the stock to keep the bag of shot from moving around. A can of foam insulation also works to hold everything in place...but can get messy if to much is used!