I have two types of Mec-Gar mags for the BHP. One is the bright blue finished standard magazine. Other than the finish, it's like the older FN mags. The second is the OEM FN mag (made by Mec-Gar), which has the spring that ejects the magazine from the gun, even if the magazine safety is intact. This one also has a very slight change in the angle at which it presents the cartridge to the ramp (it's higher). You have to put the two types side by side to see it. Supposedly, the higher angle makes it more likely that hollow-point ammunition will feed properly, even in the older guns with the humped feed ramp. Oddly, the bright blue mags drag on the magazine safety more than the FN phosphate (?) finished ones. Some day, I'll get around to checking all this out on my old High-Power. FYI, when the Belgians acquired some Inglis High Powers from Canada after WW2, they discovered that the Inglis mags had to be kept with Inglis guns and vice-versa with FN-made specimens. Also, the "standard" bright Mec-Gars are a lot cheaper than the FN-marked "mousetrap" model.