TR, that's exactly what i'll do if i can get some samples - a few 30 rnd mags or a beta through an M4, then chamber a round and let it sit for a while in a hot chamber and see what happens.
if natec ever answers my inquiries, that is.
but if it performs as advertised in all areas, it's got potential.
here's a link to a small arms symposium presentation on polymer cased 5.56:
http://www.dtic.mil/ndia/2002infantry/husseini.pdf
cheers,
MM