I concur AVOID THESE MAGS. I have returned them to TAPCO and they are good about shipping you new ones, but they are as bad as the old ones. Buy the MAGPULS they are the better mags.
AVOID THESE MAGAZINES! They are VERY hard to load past 20 rounds, And they will NOT drop free. I have a Olympic Arms 20\" Rifle, And they just barely fit into the mag-well. Get a MAG-PUL, They are only a couple bucks more and they are AWESOME.