The SR 556

[Ruger45]

I did some digging and so far this is all of the family I can come up with. I am not sure why they skipped numbers or if they didn't and I can't find the matching gun.
Anybody see any I am missing?
Model number catalog number
5901 SR 556 (M4 Type) not sure that is right
5902 SR 556 FB
5904 SR 556 SC
5905 SR 556 C
5909 SR 556 6.8
5912 SR 556 E
5913 SR 556 CLA
5914 SR 556 VT
5915 SR 556 ESC
5601 SR 762 but it is not part of the 556 family