[Grendeljaeger]

It all depends on what weapon you are trying to fit (unlike 7.62X39 & 5.54X39 there is no standard in 5.56) Each country has a slightly different feed angle and so you must fit them to the gun you will use. The German STG mags work for certain rifles and the Bulgarian and Chinese for others. Even though Galil mags fit in a Valmet they feed at a different angle and can cause the bullet to hit the top of the chamber and be pushed back into the cartridge case and cause higher chamber pressures. I would find the mag that fits and feeds and copy its front and rear lug profile. I hope this helps.