Any one fill their composite stocks with foam,I have been using plumers foam
but looking for something better.If so what do you use??

I can't give you a brand name off hand but any of the spray on types that contractors use to insulate things with should work well...

What the hell is Plumbers foam? What's it smell like?

Thats what the guy called it when I got it at a plumbing wholeseller.The name on the can is Great Stuff,they use it to seal around the holes the pipes go through,other than that I don't know.
Years ago we used to get cans of some kind of foam to redo our archery targets,it was more firmer than this foam and a differtant shade.
I have have used this ( Great Stuff) in several stocks to kill the hollow sound and it works fairly good but if it was more condensed I think it would work better. Just bought a new Rem 280 with a composite stock and wanted to know if there was something that worked better.

You can buy the 1" foam liner material like they put in instrument carrying cases to protect expensive optical equipment, that can be stuffed into the butt stock and works well too.

Malm