1990
ST 0016xx, CM forge code, raised mag fence lower, large (.312) pivot, no weep hole, no sear block, std FCG, SPORTER bolt carrier, marked COLT’S FIREARM DIVISION, barrel stamped C MP 5.56 NATO 1/7
ST 001XXX CM forge code, mag fenced lower, big pivot pin, no sear block, marked COLT’S FIREARMS DIVISION (this one has a FA carrier, bayonet lug, and tear drop forward assist, maybe replacement parts?)
GS 010173 CM forge code, slab side lower, no sear block, small hammer/trigger pins, marked COLT'S MFG CO. INC,
ST 004600 and up have large trigger/hammer pins
ST 005293 CM forge code, mag fenced lower, big pivot pin, no weep hole, sear block pinned on both sides, large hammer/trigger pins, marked COLT'S MFG CO. INC
1991
ST 007XX1 CM forge code, mag fenced lower, big pivot pin, no weep hole, no sear block, large hammer/trigger pins, marked COLT'S MFG CO. INC, barrel marked C MP 5.56 NATO 1/7, puchased new in fall of 1991
ST 008361 mag fenced lower, big pivot pin, no weep hole, sear block pinned in on both sides, marked COLT'S MFG CO. INC, this a M4gery conversion painted black
1992
ST 009999 mag fenced lower, big pivot pin
ST 010254 CM upper forge code, slab side lower, roll marked COLT'S MFG CO. INC, sear block pinned in on right side
1993 - Sept 94
ST 017XX9 mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side, this is lower only
ST 01776X CM upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side, SPORTER bolt carrier
ST 025289 CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side, SPORTER bolt carrier, blue extractor buffer
ST 026376 CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side, SPORTER bolt carrier, blue extractor buffer (purchased the summer of 94)
ST 0287XX CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side, SPORTER bolt carrier, blue extractor buffer (purchased new in September or October 1994)
ST 0289XX CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled, marked COLT'S MFG CO. INC., sear block pinned in on right side
ST 033670 mag fenced lower, small pivot pin hole, weep hole not drilled, marked COLT'S MFG CO. INC., sear block pinned in on both sides
ST 0354XX CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole not drilled, marked COLT'S MFG CO. INC., sear block pinned in on both sides
Sept 94 on (bare muzzle, and SPORTER roll markd changed to MATCH TARGET from this point)
CST 003783 CMB upper forge code, mag fenced lower, small pivot pin hole, weep hole drilled? marked COLT'S MFG CO. INC., sear block pinned in on both sides
CST 0XXXXX black finish, does not appear to have a pinned in sear block