All of the points given here are true. The thing is, many people purchase rifles with these stocks because they can't afford more. That doesn't mean you aren't getting good value but as usual with anything at bargain prices there is always something left to be desired.
I personally don't have a lot of problems with Tupperware stocks. They serve their purpose quite well but as mentioned they aren't especially conducive to pin point accuracy. Some shoot surprisingly well under certain conditions though. Usually the extreme conditions of hot/cold will cause the most issues. If you're going to hunt/shoot in late fall, don't rely on a mid summer sight in session to work well for you. It goes on. That's what's left to be desired. The money you save on the platform is expended on ammunition to sight it in more often for the conditions of use.
That being said, I have had a lot of success with bedding these stocks. First off, I don't use epoxy or glass. I have had the auto body epoxy crack and separate from stocks when the rifle is used in extreme cold, say -20C.
OK, here is what I do. I add a piece of square steel key stock behind the recoil lug. The stock has to be relieved to take the key stock and if you take out to much, it needs to be shimmed to a couple of thou above the injection molded bedding surface. Not more or it might effect feeding. The key stock has to be drilled and countersunk to accept a couple of small allen head screws and the stock needs smaller holes drilled to accept the screw tips. The screws should be of the type used for wood and don't require tapping.
With micrometer, measure how much the key stock protrudes above the bed and add a brass/steel shim to the rear of the receiver area of the stock to keep it all level. Tighten it up and you're good to go.
Some of the worst such stocks don't have receiver screw protectors on the bottom. Especially those with blind magazines or all plastic mags. In this case you can probably make up a couple of pillars as well.
Lots of things you can do but when push comes to shove, the best bet is to replace the stock with something that meets your needs/desires. Still, if it's just for hunting, most Tupperware stocks will deliver enough accuracy for clean kills out to 300 yards without problems. If it's a target rifle you're looking to make out of it, it's a waste of time.
