@ 1986s4 - They are using their own in house cast grip safety. They did use the Smith and Alexander early on but changed out to their own in order to control dimensions. The end state was to accomplish complete parts interchangeability during the M45A1 trials.
Remember with that 1991, if you're down to your last drop of lube, it goes into the upper lugs forward of the barrel hood.
Good shooting!
S/F