Just to let you all know...

WalMart now carries biodegradable .2s. Package is 5000 BBs at approximately $18. Quality yet to be checked.

Easiest way is cut one open and compare it's internals to that of a brand name BB from a place like Metaltech. The less air bubbles the better, hopefully none, and it has to be the right consistancy inside.

Exactly my thought. Waiting on payday.

Squash one with a pair of pliers. If it shatters, flakes or crumbles into large pieces, don't use them They will cause you grief with build-up in the barrel or they could break on you and lead to a torn hop-up, jammed barrel. broken nozzle and/or tappet.

If you squash them and all they do is deform, you have good BBs. You'd be surpirsed how many "quality" BBs fail to pass this simple test.

The internal consistancy is going to vary from one manufacturer to another, so I don't know what looking at the internals is really going to tell you. If you want to guage durability and performance, the squash test is the best one I know.

Cheap BB's will be crumbly inside and will have more air pockets that quality BBs.