Military Ammo Designations

M855A1 - 62gr, green tip
SS109 - Designation for the bullet loaded in M855A1
M193 - 55gr ball
M195 - Grenade launcher, no bullet, case closed with 7 pedal rose crimp, red tip
M196 - Tracer, 54gr, red tip
M197 - Test, high pressure, case stannic stained or nickel plated
M856A1 - Tracer, 64gr, orange tip
M199 - Dummy round, 6 corrugations impressed into the case
XM200 - Blank, mouth closed with 7 pedal rose crimp
M232 - Dummy, inert loaded, 55gr, cartridge chemically blackened
M857 - Dummy, inert loaded, 62gr, cartridge chemically blackened

Seems like most of the confusion comes from the SS109 / M855 area.
The SS109 is the bullet that is loaded in the M855 round. Hope this helps.