I know the Sig Combat series and the MK25 use the 1913 rail why doesn't Sig get along with the rest of the world and use the 1931 rail on all their railed guns?

I prefer the 1913 over the Sig rail everyday and twice on Sunday! Is there and up sides to using the Sig rail over the 1913 rail? I can't think of any...

Thoughts......

Because the SIG proprietary rail is not as large and bulky, and blends in with the pistol better. It’s perhaps not as suitable for hanging an 18-pound night vision device and 44×103mm scope sight from as the “real” Picatinny rail is, but it’s perfectly suitable for a laser and/or light.