Adding Weight to a Stock?

I got my two $58 clearance thumbhole stocks from Stockys and they look quite nice. They are unfinished and I have started to prep one of the stocks for a barrel action from a rifle in another stock. Since this will rifle/stock set-up will be for shooting prairie dogs from off the bench I would like to make it heavier. The donor action is a single shot and the stock has a blind magazine plus the area underneath the barrel channel has a slot milled out. I would like to fill these areas with some material to add weight. My first thought was to melt and add lead but I see the melting point is 621.5 f. and thought this would burn the stock. You guys know what material is used to add weight to stocks.

I like epoxy and #12 shot soup....works for me....

You could pour lead if you do it a bit at a time. not near as smooth as a single pour. I did do it to one of mine.

Epoxy and lead would give you a smooth finish

Not sure what caliber it's for but how about a recoil reducer in the buttstock?

http://www.brownells.com/.aspx/pid=6...DUCTION_SYSTEM

Mag well: Fold top sandwich bags. One inside the other. Add lead shot. As much or little as you want. The bags are soft enough to fit the contour of the mag well and strong enough not to come apart. Put the bags in the mag well, pour in the lead shot. Fold the top over. Pack it with whatever you want. Make it high enough that the action will compress the packing. Too heavy? Take some out. Not heavy enough? Add more shot. Epoxy and shot is more of less a one shot deal. Suppose somewhere down the road you decide to sell the stock or get a repeater action? Pull the bag of shot and you're good to go. ;)
Lead shot and epoxy in the forend grove? Another one shot deal but not sure what else you could do.
Try to balance the rig just at the front of the barrel nut. Good luck. ;)