a short list of bolts made from mil-spec steel.
colt 158 MPI
DD 158 MPI
LMT 158 MPI
SABER 158 MPI
Bravo company USA 158/mpi
CMT 158 and other brand names that use CMT products like stag & RR some are MPI some not.
older DPMS. olympic and bushmaster may have been 8620 in the past-- i can't so far confirm this??
some of the UBER-tanium bolts use 9310 steel and have some improvements including thicker web portions and so on. some my have a nitrogen type coatings. expect to shell out a $100 bill for one.
it might be a shorter list to find the makers of the softer 8620 bolts?
anybody want to add to the list?