Let's reset. Are you talking about plate to gun, or optic to plate?
Plate to gun - use the screws that came with the cover.
407k to plate: The M4x0.7 screws that came with the 407K should work. Ideally you want 8 or 9mm length, I think. Test them by mounting the optic to the plate OFF the gun and see if they fully engage or protrude. Any protrusion is bad, and you don't need "flush" engagement if you've got more than a couple of threads in.
Plate to gun - use the screws that came with the cover.
407k to plate: The M4x0.7 screws that came with the 407K should work. Ideally you want 8 or 9mm length, I think. Test them by mounting the optic to the plate OFF the gun and see if they fully engage or protrude. Any protrusion is bad, and you don't need "flush" engagement if you've got more than a couple of threads in.
