Markings per component:
-Barrel Bands
-Type 1 (Early Narrow Band)
-Inland: Marked "UI" "U" Or unmarked.
.....Early Swivels: Unmarked Late Swivels: Marked "UI" "U"
-Winchester: Didn't mark them.
.....Swivels: Unmarked
-Underwood: Didn't mark them.
.....Swivels: Unmarked
-Rock-Ola: Marked "MR" "UR"
.....Swivels: Unmarked
-Quality Hardware: Marked "QU" Q-TX" "UI" Or unmarked.
.....Early Swiviels: Marked "QU" Late Swivels: Marked "QU" "QTK"
-NPM: Marked "UI" "U" Or unmarked.
.....Late Swivels: Marked "UN"
-S.G.: Didn't mark them.
.....Swivels: Unmarked
-S'G': Didn't mark them.
.....Late Swivels: Marked "U-S'G'" "KV-S'G'"
-IP: Didn't mark them.
.....Late Swivels: Marked "UP"
-I.B.M.: Marked "KV-B"
.....Late Swivels: Marked "KV-B" Or Unmarked
-Standard Products: Didn't mark them.
.....Swivels: Unmarked
-Type 2 (Wide Band)
-Inland: "AI" "KI" "II" "/" "-" "PI" inside a triangle, or unmarked.
-Underwood: Didn't mark them.
-Winchester: Didn't mark them.
-Rock-Ola: "|" or unmarked.
-NPM: Didn't mark them.
-S.G.: Didn't mark them.
-S'G': Never made them.
-IP: Never made them.
-I.B.M.: "//" or unmarked.
-Standard Products: Didn't mark them.
-Quality Hardware: Didn't mark them.
-Type III, T-4 (bayonet lug)
-Inland: "AI" "KI" "SI" "H.I." "JI" "UI"
-Winchester: "C"
-No other WWII contractor made these.
---Other WWII Markings: "AMCO" "JM" "SA" "MMQ" "C" "GM" "Q" | Diamond with a "D" in
it. Or unmarked.
---Post WIII Markings: Circle with a "A" in it.
-Rear Sights
-Type I (Flip Sight) The "S" on the Left base, stood for small side.
-Inland: Right base: Unmarked | Left base: "S" "S~" "WSI" squiggly "S" | Leaf: "W.I."
or unmarked.
-Winchester: Right base: Unmarked | Left base: Squared "S" or unmarked | Leaf:
unmarked.
-Underwood: Right base: Unmarked | Left base: "S" Squared "S" | Leaf: ".U."
-Quality Hardware: Right base: "GE-Q" "B-Q" | Left base: "S" | Leaf: unmarked.
-Rock-Ola: Right base: "A-R" "BR" "RR" | Left base: "S" | Leaf: "AR" "BR" "RR" or
unmarked.
-NPM: Right base: "N-A" "TN" "RN" "PB" | Left base: "S" | Leaf: "RN" ".U." "TN"
-Standard Products: Right base: Unmarked | Left base: "S" | Leaf: ".U." or unmarked.
-I.B.M.: Right base: "WB" "IN-B" "FOB" or unmarked | Left base: "S" | Leaf: unmarked.
-S.G.: Right base: unmarked | Left base: "S" squared "S" or unmarked | Leaf: ".U."
-S'G': Right base: "B-S'G'" "W-S'G'" "RG-S'G'" | Left base: "S" | Leaf: "B-S'G'" "RG-
S'G'"
-IP: Right base: "IP-B" "B-IP" "RP" | Left base: "S" | Leaf: "RP" "B-IP" "IP-B"
-Type II (Milled adjustable rear sight)
-Inland: "HI" "PI"
-Winchester: "CH" an "H" in a shield.
-Rock-Ola: an "H" in a shield.
-S.G.: "PI"
-Standard Products: an "H" in a shield.
-I.B.M.: an "H" in a shield.
-No other contractor made these
-Type III (Stamped adjustable rear sight)
-Inland: "I.R. CO. 7160060" "I.R. CO." "J.A.O." "J.A.O. 7160060"
-Winchester: "I.R. CO. / an "H" in a shield.
-Rock-Ola: "I.R. CO." / an "H" in a shield.
-Quality Hardware: "I.R. CO."
-I.B.M.: "I.R. CO. 7160060"
-----Post WWII markings: "SA" "71600060" "J.A.O." "I.R. Co. 7160060"
-Front Sights
-Type 1
-Inland: Marked Top: "N" "SI" "N.I." "R" A sideways "N"
-Winchester: Unmarked or Marked Right Side: "L"
-Rock-Ola: Marked Front: "RP" "TR" "R"
-Underwood: Marked Top: ".U." "TR" | Marked Front: ".U."
-NPM: Marked Top: "NN" "NI" "N"
-I.B.M.: Marked Top: "N" "TR"
-Quality Hardware: Marked Top: "N" "Z" "JQ" "QJ"
-Saginaw (S.G.):Marked "SG"
-Saginaw (S'G'): Marked Top: "N-S'G'" "S'G'" "N" | Marked Left side: "2 - 7"
-IP: Marked Top: "IPN" "N" | Marked Left side: "2 - 7"
-Standard Products: Marked Top: "SN" "N"
-Type II (Fabricated)
-I.B.M.: Marked Top: "SI-B" "PO-B" | Marked Right Side: "POB EU"
-NPM: Marked Top: "SN"
-Underwood: Marked Top: "EU" "SIU"
-Rock-Ola: Marked Top: "RP"
-Quality Hardware: Marked Top: "PO-Q"
-Saginaw (S.G.): Marked Right Side: "PO" "SG"
-Type III (Post War)
-Could be marked: "SA" "RIA" "P" "R"
-Bolts
-Type I (Flat Bolt)
-Inland: Right Lug, Marked "IO" in a circle, or the flaming bomb
-Winchester: Right Lug, Unmarked / Punch Mark
-Type II (Flat Bolt)
-Inland: Left Lug, Marked "IO" "OI" "AI" "IO" in a circle
-Winchester: Right Lug, Marked: "W" or Punch Mark
-Rock-Ola: Left Lug, Marked: "ROCK-OLA". | Right Lug, marked: "UN-R" "R" "ROCK-OLA"
-Underwood: Right Lug, Marked: ".U." "SU" "CU" "WU"
-Saginaw (S.G.): Left Lug, Marked: "SG"
-Saginaw (S'G'): Right Lug, Marked: "S'G'"
-Irwin-Pederson: Right Lug, Marked: "IP"
-Quality Hardware: Right Lug, Marked: "EM-Q" "UN-Q"
-Standard Products: Right Lug, Marked: "S" with numbers.
-NPM: Left Lug, Marked: "UN-N" "N" with increasing numbers.
-I.B.M.: Right Lug, Marked: "SB" "AOB"
-Type III (Round Bolt)
-Inland: Left Lug, Marked: "OI" "SI" "AI, with numbers"
-Winchester: Right Lug, Marked: "W"
-Underwood: Right Lug, Marked: ".U." "WU" "CU" "SU"
-Rock-Ola: Left Lug, Marked: "ROCK-OLA"
-Quality Hardware: Right Lug, Marked: "EM-Q"
-Saginaw (S.G.): Left Lug, Marked: "SG"
-I.B.M.: Right Lug, Marked: "EM-B" "SB" "AOB"
-Extractors
-Type I (Early)
-Inland: Marked "WI"
-Winchester: Marked "W"
-Rock-Ola: Marked "R"
-Underwood: Marked ".U."
-Type II (Modified)
-Inland: Marked "WI" "SI"
-Underwood: Marked ".U."
-Winchester: Marked "W"
-Type III (Late)
-Inland: Marked "WI" "W-I"
-Winchester: Marked "W"
-Underwood: Marked ".U." "MU" "KU"
-Rock-Ola: Marked "R" "R-SG"
-Standard Products: Marked "WI" "S" "SW"
-NPM: Marked "N" "IN"
-Quality Hardware: Marked "ST-Q" "WQ"
-Saginaw (S.G.): Marked "WSG" "SG"
-Saginaw (S'G'): Marked "W-S'G'" "S'G'" "I-S'G'" "IP-W"
-Irwin Pederson: Marked "IP-W" "S'G'" "W-S'G'" "I-S'G'"
-I.B.M.: Marked "IB" "WB" "W-B"
-Firing Pins
-Type I
-Winchester: Marked "W"
-Inland: Marked "I-I" "NI" "BI" "WI" "RI"
-Rock-ola: Marked "ROCK-OLA" "R"
-Underwood: Marked "DU" "WU" ".U."
-NPM: Marked "NN" "WN"
-Quality Hardware: Marked "NL-Q" "NQ" "HS" "B-Q"
-Saginaw (S.G.): Marked "SG"
-Saginaw (S'G'): Marked "S'G'"
-Irwin Pederson: Marked "IP"
-I.B.M.: Marked "BEB" "BTB" "BR-B" "OBB" "SUB" "WB" "WB" "OB-B"
-Standard Products: Marked "HS" "WS" "SDP"
-Type II
-Inland: Marked "RI" "C" "NI"
-Underwood: Marked "DU" ".U." "WU"
-Winchester: Marked "W"
-NPM: Marked "NN" "N-N"
-Standard Products: Marked "SDP"
-I.B.M.: Marked "BT-B" "BEB" "SUB" "SWB"
-Type III
-Rock-Ola: Marked "ROCK-OLA"
-Winchester: Marked "W"
-Inland: Marked "NI" "I-I" "SI" "R.I." "RI"
-Underwood: Marked "DU" ".U." "WU"
-NPM: Marked "DN" "N-N"
-Saginaw (S.G.)" Marked "SG"
-Quality Hardware: Marked "N-Q" "NLQ"
-Standard Products: Marked "SDP"
-I.B.M.: Marked "BTB" "BEB" "OBB" "OB-B" "WB" "SUB" "WB"
-Slides
-Type I (Arm Joint 11/32")
-Inland: Marked in slide well "PI" "PI" In a circle
-Winchester: Marked in slide well "W"
-Underwood: Marked in slide well ".U." ".U. in a circle" "O.U." In a circle
-Rock-Ola: Marked on bottom "ROCK-OLA"
-Quality Hardware: Marked in slide well "DA-Q"
-NPM: Marked in slide well "N (with a number)"
-Type II (Arm Joint 7/32")
-Inland: Marked in slide well "PI" "PI" in a circle
-Winchester: Marked in slide well "W"
-Underwood: Marked in slide well ".U." "WU" "O.U." "F(in a heart).U."
-Rock-Ola: Marked in slide well "PI R" Marked on bottom "ROCK-OLA"
-Quality Hardware: Marked in slide well "DA-Q"
-NPM: Marked in slide well "N (with a number)"
-Irwin Pederson: Marked in slide well "IP"
-Saginaw (S.G.): Marked in slide well "SG" Marked on bottom "SG"
-Saginaw (S'G') Marked in slide well "S'G'"
-I.B.M.: Marked in slide well "19AOB" "AOB" "PI"
-Standard Products: Marked in slide well "S" in a cirlce
-Type III (Arm Joint 19/32")
-Inland: Marked in slide well "PI"
-Underwood: Marked in slide well "WU" "O.U." in a cirle
-Winchester: Marked in slide well "W"
-Rock-Ola: Marked in slide well "UN-R" Marked on bottom "ROCK-OLA"
-Quality Hardware: Marked in slide well "UN-Q"
-NPM: Marked in slide well "N (with a number)" "UN"
-S.G.: Marked on bottom "SG"
-I.B.M.: Marked in slide well "AOB"
-Standard Products: Marked in slide well "S" "S" in a circle
-Type IV
-Inland: Marked in slide well "PI" Marked on bottom "7160091"
-Winchester: Marked in slide well "W" Marked on bottom "7160091" "7161843"
-Type V (M2 Full auto)
-Inland: Marked in slide well "PI" Marked on bottom "7161843"
-Winchester: Marked in slide well "W" Marked on bottom "7160091" "7161843"
-Trigger Housings
-Type I (Double Bevel)
-Inland: Marked "Inland"
-Winchester: Marked "W"
-Underwood: Marked ".U." in the magazine well
-Rock-Ola: Marked "ROCK-OLA"
-NPM: Marked "N" on right side (a number) on the left side
-Type II (Single Bevel)
-Inland: Marked "Inland"
-Underwood: Marked ".U."
-Winchester: Marked "W"
-Rock-Ola: Marked "ROCK-OLA"
-NPM: Marked "N (with a number)
-Quality Hardware: Marked "Q-NL"
-Saginaw (S'G') Marked "S'G'"
-Irwin Pederson: Marked "IP"
-Type III (Type III are the same as Type II except they do not have the bevels on rear
lug)
-Inland: Marked "Inland" (vertically)
-Winchester: Marked "W (with number or letter)
-Underwood: Marked ".U."
-Saginaw (S.G.) Marked "S.G."
-Saginaw (S'G') Marked "S'G'"
-Quality Hardware: Marked "Q-NL"
-Standard Products: Marked "S (with a number)"
-Type IV (Fabricated)
-Inland: Marked "Inland"
-Underwood: Marked ".U."
-Rock-Ola: Marked "ROCK-OLA"
-Quality Hardware: Marked "Q-TX"
-I.B.M.: Marked "B-EB" "BE-B" "Q-TX" "BE-IB"
-Standard Products: Marked "ST" "BE-B"
-Type V (Oil Hole)
-Inland: Marked "Inland" (vertically)
-Winchester: Marked "W (with a number)"
-Type VI (M2 Full auto)
-Inland: Marked "Inland" (upside down)
-Winchester: Marked "W" "A (with a number)"
-No other contractors made these, how ever some early trigger housings were converted
to M2 Trigger housings
-Triggers
-Early
-Inland: Marked on right side "R.I."
-Winchester: Marked on right side "W"
-Rock-Ola" Marked on left side "ROCK-OLA"
-Quality Hardware: Marked on right side "Q-LT"
-Late
-Inland: Marked on right side "R.I." "FI" "RHI"
-Winchester: Marked on right side "W"
-Rock-Ola: Marked on left side "ROCK-OLA"
-Underwood: Marked on right side ".U." "JU"
-Quality Hardware: Marked on right side "LT-Q"
-NPM: Marked on right side "SN" "N"
-Saginaw (S'G'): Marked on top "S'G'"
-Saginaw (S.G.): Marked on left "SG"
-Irwin Pederson: Marked on top "IP"
-Standard Products: Marked on right "S-HR" "SA" "S-C"
-I.B.M.: Marked on right side "SKB" "HR" "SN" "TB" "PDB" "JU"
-Sears
-Type I
-Winchester: Marked "W"
-Inland: Marked "R.I." "RI" "SI" "BI" (BI for Inland is small letters)
-Underwood: Marked ".U."
-Rock-Ola: Marked "R" "ROCK-OLA"
-NPM: Marked "SWN" "BOB" "BN" "LN"
-Quality Hardware: Marked "BOB" "GE-Q"
-Saginaw (S.G.) Unmarked
-Saginaw (S'G') Marked "SW" "S'G'"
-Irwin Pederson Marked "IP-SW" "SW-IP"
-Standard Products: Marked "SDP" "SD" "SW"
-I.B.M.: Marked "BOB" "SG-B" "SWB" "GB" "BI" (BI in big letters is for I.B.M.)
-Type II (With hole or grind mark)
-Inland: Marked "R.I." "RI" "DI" "XI" "BI"
-Winchester: Marked "W"
-Rock-Ola: Marked "ROCK-OLA"
-Underwood" Marked "G.U." ".U."
-Standard Products: Marked "SDP" "SW"
-NPM: Marked "SW-N"
-Quality Hardware: Marked "QA" "SE-Q" "BOB" "GE-Q"
-I.B.M.: Marked "SW" "SDP" "GB" "BI"
-Type III (M2, Full Auto)
-Inland: Marked "RI" "HI"
-Winchester: Marked "W"
-Hammers
-Type I (Dog Leg)
-Inland: Marked "H" "HI" "H.I." "GI" "H" in a shield | Flaming bomb
-Winchester: Marked "W"
-Underwood: ".U."
-Rock-Ola" Marked "KR"
-NPM: Marked "HIN" "N"
-Saginaw (S'G'): Marked "S'G'"
-Irwin Pederson: Marked "IP"
-Type II (Dog Leg)
-Winchester: Marked "W"
-Inland: Marked "NI" "HI"
-Underwood: Marked ".U."
-Rock-Ola: Marked "KR" "I.K."
-NPM: Marked "N" "HI" "HN" "H" in a shield
-Quality Hardware: Marked "Q" "LT"
-Saginaw (S.G.): Marked "KR" with a C in a circle
-Irwin Pederson: Marked "IP"
-Saginaw (S'G'): Marked "S'G'"
-Standard Products: Marked "SW" "KR" "HI"
-Type II-A (Fat Boy)
-Inland: Marked "IN"
-Rock-Ola: Marked "KR"
-NPM: Marked "NI"
-Saginaw (S'G'): Marked "S'G'"
-Type III (Straight)
-Inland: Marked "I-I" "WI" "NI"
-Winchester: Marked "W" "WS"
-Rock-Ola: Marked "KR" "KR2" "R-LT" "LTR" "Q" "I.K." "S/R" "KR" in a diamond
-Underwood: Marked ".U." "O.U." "WU"
-Quality Hardware: Marked "HN" "IN" "AQ" "Q.U." "NHTE"
-NPM: Marked "SG" "Z"
-Saginaw (S.G.): Marked "S.G."
-Saginaw (S'G'): Marked "S'G'"
-Standard Products: Marked "SW" "SHTE" "SS"
-I.B.M.: Marked "GMB" "AMB" "WMB"
-Type IV (M2 Full Auto)
-Inland: Marked "I-I"
-Winchester: Marked "W"
------WWII Replacement Hammer Markings------
- "B/R" Brunner/Ritter
- "W" White Sewing Co.
- "W A" Walt Manufacturing Co.
-Safeties
-Type I (Checkered Face)
-Used by Inland, Winchester, Underwood, Rock-Ola. All were unmarked.
-Type II
-NPM: Marked inside "IN"
-Saginaw (S'G') & Irwin Pederson: Marked outside "IPW" "IPA"
-Winchester, Inland, Underwood, Rock-Ola, Quality Hardware, Saginaw (S.G.) also used
this safety but were unmarked.
-Type III
-Winchester: Marked outside "SW" ""EW""
-Quality Hardware: Marked inside "EP-Q" "Q-NL"
-NPM: Marked inside "IN" Marked outside "TN" "SN"
-Saginaw (S.G.) Marked outside "SG"
-Saginaw (S'G') Marked outside "E-S'G'" "S'G'"
-Standard Products: Marked inside "S-MP" Marked outside "SW"
-I.B.M.: Marked inside "W-B" "EP-B" "ER-B" Marked outside "WB" "EP-B" "ER-B"
-Inland, Rock-Ola, Underwood used these but were unmarked.
-Type IV (Rotary | Flip)
-Winchester: Marked outside "W" "EW"
-Inland: Marked "HI" "EI"
-----Post War Type IV Markings------
- "H.T." "J.A.O." "P" "N" "CM" "M" in a circle or unmarked
-Magazine Catches
-Type I (Serrated)
-Winchester: Marked "W"
-Inland: Marked "WI"
-Rock-Ola: Marked "BR" "FR"
-Type II (Long Plain Face)
-Inland: Marked "WI" "EI"
-Winchester: Marked "W"
-Underwood: Marked ".U."
-Rock-Ola: Marked "A-R" "BR" "FR"
-Type II-A (Short Serrated)
-Inland: Marked "W.I."
-Underwood: Marked ".U."
-Type III (Short Plain Face)
-Inland: Marked "WI" "EI"
-Underwood: Marked ".U." "AU"
-Rock-Ola: Marked "A-R" "FR" "BR"
-Winchester: Marked "W"
-NPM: Marked "MN" "SN"
-Quality Hardware: Marked "LT-Q" "EPQ" "TQ"
-Saginaw (S.G.): Marked "SG" "ESG" "WSG" "ISG" "T with S.G. under it" "E with S.G.
under it"
-Saginaw (S'G'): Marked "S'G'" "E-S'G'" "W-SG"
-Irwin Pederson: Marked "BIP" "IPB" "IP-W" "P-IP" "EIP"
-Standard Products: Marked "SW"
-I.B.M.: Marked "EPB" "PR-B"
-Type IV (Narrow Wall | has a "M" on face)
-Winchester: Marked "W" ""EW""
-Inland: Marked "EI" "SI" "WI" "HI"
-Saginaw (S.G.): Marked "TSG" "ISG" "W with S.G. under it"
-Type V (M2 Full Auto has M on face)
-Winchester: Marked "W"
-Inland: Marked "EI" "WI"
-Recoil Plates
-Type I (Prototypes)
-Inland, Winchester, None were marked
-Type II
-Winchester: Marked "W"
-Inland: Marked "W-I" "DI" "D.I."
-Underwood: Marked ".U."
-Rock-Ola: Marked "R" "ROCK-OLA"
-NPM: Marked "LN"
-Quality Hardware: Marked "RO-Q"
-Irwin Pederson: Marked "IP-W"
-Saginaw (S'G'): Marked "W-P" "W-S'G'"
-Saginaw (S.G.) Marked "SG"
-Standard Products: Marked "SW" "RT" "STANDARD PRODUCTS"
-Type III
-Inland: Marked "W.I." "PI" "DI" "D.I."
-Winchester: Marked "W"
-Rock-Ola: Marked "ROCK-OLA" "R with an SG under it
-Underwood: Marked ".U." "AU"
-NPM: Marked "LN" "PN"
-Saginaw (S.G.) Marked "SG"
-Saginaw (S'G') Marked "W-P" "W-S'G'"
-Irwin Pederson: Marked "WP"
-I.B.M.: Marked "PR-B" "BB"
-Standard Products: Marked "STANDARD PRODUCTS" "SW" "SWI"
-Quality Hardware: Marked "RO-Q"
