Cabelas has PMag 20LR mags back in stock for you .308 guys at the normal price of $19.99 each.
http://www.cabelas.com/product/Magp...s&Ntt=magpul&WTz_l=Header;Search-All+Products
http://www.cabelas.com/product/Magp...s&Ntt=magpul&WTz_l=Header;Search-All+Products