I tried them all. For 10 rounders, mecgar and brownells are 90% good. WC and tripp research are 100% functional, metal form is bolt action, and so is kimber. Suprisingly, the norinco 9 rounder is 100% as well, but they are 9 rounds.
If you can get WC, get the ETM, its not worth the extra 10-15$ for the vickers version.
1 of the thing to watch out for us the slide stop, make sure the gun has the extended lip on the inside, where the follower tab pushes against, some manufacturers, ie norinco just slap a 45acp one on and hope it works.