Weve talked about making our own glock 18, just to play with, but never have. Ammo got tough the first time about when we were talking about it, plus, we were wanting a cheap used gun to come in to do it with, since "once a machinegun, always a machinegun".
However, there are other internal differences. The slide is a bit heavier, and the rails sit higher up inside than a standard 17.
Which kind of sucks for glock, since they have a g18 in smyrna with a cracked slide, and atf wont let them import parts, only whole guns, so they so far had been unable to fix it.