I'm painting an old 700 plastic tupperware stock and would like to fill the hollow back end with a lightweight material (foam) mainly for noise dampening but also to give it a more solid feel.

Any recommendations on products that work well? Plenty of cans of "Great Stuff" laying around which is the default solution at this point.

This stuff is 5.5lbs per gallon



3m filler

The "Great Stuff" spray foam would be my first choice unless you want to add a bunch of weight to the stock/rifle. I pulled the 6oz epoxy/silicone plug from the butt of my Kimber hunter and filled it with spray foam. Worked great.

I used Great Stuff on my 700 Tupperware stock and worked great......

Be careful with the high expansion foam.
It's expansion is stronger than your stock.
Be really careful if you shoot it up around the pistol grip.
Either minimally expanding, or just be cautious.

I used Gorilla Glue to glue .50 cal lead balls into a hollow stock. That was about 2006. The Gorilla Glue is still holding the balls. GG foams up when it comes in contact with a bit of water, and little goes a long long way.

I use Great Stuff. Fill a little bit,let expand .Repeat a little bit at a time so you don't get pressure from expansion. I have used Air Soft Beads mixed with Acrucglas to fill the slots in the barrel channel to stiffen it up with an old carbon fiber arrow piece layed in with it.

Use the door and window foam... it doesn't expand as much.

Plastic Walmart bags.

Had a plastic butt on a 336 that rang like a drum............ just used a couple of old wash rags.......

Expanding foam for sealing windows, doors etc. I have done two stocks this way. My muzzleloader, I also put a couple large bolts in there to add weight, and balance the rifle better. Maybe 2 or 3 3/4 x 4" bolts. Worked great.


You have to leave the butt plate off until the foam has expanded and hardened....or it won't.

Then simply trim the excess away and refit you buttplate.

The window and door Great Stuff is what I use. Done several Tikka T3 and a couple other for people. As Skatchewan said leave the butt plate off until it cures then trim, should be about 24 hours. And don't go too far toward the trigger either...Tikkas had a hole there and it was a bear trying to get it clear before putting the barrel and trigger back in. Foam before painting...it will pull the paint if you get it on the stock. Trust me, I ended up redoing a 4 color Duracoat job for forgetting to do it ahead of time.

I filled my new camo 870 stock with doubled up quart freezer bags full of bird shot. The stock didn't hold very much, but it tamed the recoil some and made the balance better, for me anyway. I just made sure to use plenty of gorilla tape on them so nothing would come loose. If you don't want that much weight , you could use sand or cat litter......clean of course...