HRA | Aperature | B8868-1 | Type 3 | January/1953 to December/1956 | 4660001 - 6034729 | Late version. Squared ramp shoulders below aperature disk. Wide tracks (0.085 inches wide). Edges of aperture disk smoothly finished. |
HRA | Elevating Pinion | N/A | Type 4 | January/1953 to December/1956 | 4660001 - 6034729 | Postwar with 8-36NF thread, no locking bar |
HRA | Elevation Knob | N/A | Type 2 | January/1953 to December/1956 | 4660001 - 6034729 | Postwar, integral part of pinion, may be marked "HRA-W" or "HRA". |
HRA | Front Site | B147427 | Type 3A | January/1953 to December/1956 | 4660001 - 6034279 | 0.687 width at blades. |
HRA | Front Site Screw | N/A | Type 3 | January/1953 to December/1956 | 4660001 - 6034729 | Non-rebated head. Head may be smooth or knurled. |
HRA | Rear Sight Base | C46001 | Type 2 | January/1953 to December/1956 | 4660001 - 6034729 | Unmarked. |
HRA | Rear Sight Cover | B8872 | N/A | January/1953 to December/1956 | 4660001 - 6034729 | Similar to Type 2 SA. Indentations struck deeper. |
HRA | Rear Sight Lock Nut | N/A | Type 3 | January/1953 to December/1956 | 4660000 - 6034729 | Windage knob nut. |
IHC | Aperature | B8868-1 | Type 3 | January/1953 to December/1956 | 4400000 - 5278245 | Late version. Squared ramp shoulders below aperature disk. Wide tracks (0.085 inches wide). Edges of aperture disk smoothly finished. |
IHC | Elevating Pinion | N/A | Type 4 | January/1953 to December/1956 | 4400000 - 5278245 | Postwar with 8-36NF thread, no locking bar |
IHC | Elevation Knob | N/A | Type 2 | January/1953 to December/1956 | 4400000 - 5278245 | Postwar, integral part of pinion, may be marked "IHC DRC". |
IHC | Front Site | B147427 | Type 3C | January/1953 to December/1956 | 4400000 - 5278245 | 0.875 inches wide at blades. Widest of all manufactured. |
IHC | Front Site Screw | N/A | Type 3 | January/1953 to December/1956 | 4400000 - 5278245 | Non-rebated head. Head may be smooth or knurled. |
IHC | Rear Sight Base | C46001 | Type 2 | January/1953 to December/1956 | 4400000 - 5278245 | may be stamped "A" or "C" |
IHC | Rear Sight Cover | B8872 | N/A | January/1953 to December/1956 | 4400000 - 5278245 | Similar to Type 2 SA. |
IHC | Rear Sight Lock Nut | N/A | Type 3 | January/1953 to December/1956 | 4400000 - 5278245 | Windage knob nut. |
SA | Aperature | B8868-1 | Type 1 | January/1936 to November/1939 | 1 - 20000 | Gas trap, no tracks on bottom surface on either side of the teeth. Drawing number "B8868-1" stamped on upper curved surface. |
SA | Aperature | B8868-1 | Type 2 | November/1939 to February/1940 | 20000 - 28000 | No tracks on the bottom of either side of the teeth and drawing number omitted. |
SA | Aperature | B8868-1 | Type 3-1 | February/1940 to December/1957 | 28000 - 6100500 | Early version. Rounded ramp shoulders below aperature disk. Narrow tracks (0.065 inches wide). |
SA | Aperature | B8868-1 | Type 3-2 | February/1940 to December/1957 | 28000 - 6100500 | Late version. Squared ramp shoulders below aperature disk. Wide tracks (0.085 inches wide). Edges of aperture disk smoothly finished. |
SA | Aperature | B8868-1 | Type 4/5 | December/0 to December/0 | 0 - 0 | NM. Part#s 7268110(0.0520 inch peep hole) and 7268109(0.0595 inch peep hole). Type 5 was the hooded NM version. |
SA | Elevating Pinion | N/A | Type 1 | January/1936 to March/1942 | 1 - 540000 | Short with 6-40NF thread, with flush nut. Early examples (to circa 46,000-47,00) were marked inside with the part number. |
SA | Elevating Pinion | N/A | Type 2 | March/1942 to November/1942 | 540000 - 1000000 | Short, same as Type 1 but with locking bar substituted for flush nut, 6-40NF thread. |
SA | Elevating Pinion | N/A | Type 3 | August/1942 to June/1945 | 800000 - 3800000 | Long with 8-36 NF thread, with locking bar. |
SA | Elevating Pinion | N/A | Type 4 | June/1945 to December/1957 | 3800001 - 6100500 | Postwar with 8-36NF thread, no locking bar |
SA | Elevation Knob | N/A | Type 1A | January/1936 to July/1940 | 1 - 47000 | Part number inside, checkered rim with closed arrowheads. |
SA | Elevation Knob | N/A | Type 1B | June/1940 to September/1942 | 46000 - 850000 | No part number, checkered rim with closed arrowheads. |
SA | Elevation Knob | N/A | Type 1C | September/1942 to October/1945 | 850000 - 3888081 | Knurled rim, closed arrowheads. |
SA | Elevation Knob | N/A | Type 2 | January/1952 to December/1957 | 4206000 - 6099905 | Postwar, integral part of pinion. May be marked "SA" in late 1950s+ |
SA | Front Site | B147427 | Type 3A | July/1940 to December/1957 | 50001 - 6100500 | Between 0.625 and 0.687 inches wide at blades. Smaller dimension usually associated with WWII. |
SA | Front Site | B8882 | Type 2A | January/1936 to July/1940 | 81 - 50000 | Straight guard blades. Front site blades not rounded, rear of blade is quarter circle shaped. No vertical slot it guard blade. |
SA | Front Site | B8882 | Type 2B | January/1936 to July/1940 | 81 - 50000 | Flared guard blades. Front site blades not rounded, rear of blade is quarter circle shaped. No vertical slot it guard blade. |
SA | Front Site | Unknown | Type 1 | January/1936 to January/1936 | 1 - 80 | Single blade without guards, gas trap pre production rifles only. |
SA | Front Site Screw | N/A | Type 1 | January/1936 to July/1940 | 1 - 50000 | Gas Traps only. |
SA | Front Site Screw | N/A | Type 2 | July/1940 to February/1943 | 50001 - 1360000 | Rebated Allen socked head, used with seal. |
SA | Front Site Screw | N/A | Type 3 | March/1943 to December/1957 | 1360001 - 6100500 | Non-rebated head. Head may be smooth or knurled. |
SA | Rear Sight Base | C46001 | Type 1A | January/1936 to January/1940 | 1 - 25000 | "C46001" stamped on the flat underside, machined with a rounded area behind hole for elevation/windage knob shaft. |
SA | Rear Sight Base | C46001 | Type 1B | January/1940 to October/1940 | 25000 - 75000 | No "C46001" stamped on the flat underside, machined with a rounded area behind hole for elevation/windage knob shaft. |
SA | Rear Sight Base | C46001 | Type 2 | October/1940 to December/1957 | 75001 - 6100500 | No "C46001" stamped on the flat underside, machined with a "squared" off area behind hole for elevation/windage knob shaft. No concentric ring around hole for elevation pinion/windage knob assembly. |
SA | Rear Sight Cover | B8872 | Type 1A | August/1937 to April/1939 | 81 - 10000 | Smooth, no reinforcing indentations along top and sides. Was marked "B-8872". |
SA | Rear Sight Cover | B8872 | Type 1B | April/1939 to November/1939 | 10000 - 20000 | Smooth, no reinforcing indentations along top of sides. Was marked "B-8872". |
SA | Rear Sight Cover | B8872 | Type 1C | November/1939 to July/1940 | 20000 - 50000 | Smooth, no reinforcing indentations along top and sides. Was marked "8872". |
SA | Rear Sight Cover | B8872 | Type 1D | July/1940 to December/1940 | 50000 - 95000 | Smooth, no reinforcing indentations along top and sides. Not marked. |
SA | Rear Sight Cover | B8872 | Type 2 | December/1940 to December/1957 | 95001 - 6100500 | No drawing number marked. Reinforcing indentations on top and edges. |
SA | Rear Sight Lock Nut | N/A | Type 1 | January/1936 to March/1942 | 1 - 530000 | Flush nut, short pinion, 6-40NF thread |
SA | Rear Sight Lock Nut | N/A | Type 2A | March/1942 to November/1942 | 530001 - 1000000 | Locking bar, short pinion, 6-40NF thread, with rounded ends and rounded binding ridges. |
SA | Rear Sight Lock Nut | N/A | Type 2B | November/1942 to January/1944 | 1000001 - 2500000 | Locking bar, long pinion, 8-36NF thread, with rounded ends and rounded binding ridges. |
SA | Rear Sight Lock Nut | N/A | Type 2C | January/1944 to October/1945 | 2500001 - 3890000 | Locking bar, long pinion, 8-36NF thread, with squared ends and squared binding ridges. |
SA | Rear Sight Lock Nut | N/A | Type 3 | January/1952 to December/1957 | 4206000 - 6100500 | Windage knob nut, no locking bar, 8-36NF thread with square ends and square binding ridge. |
WRA | Aperature | B8868-1 | Type 1 | December/1940 to January/1945 | 100101 - 2540999 | Parkerized stamped steel. May have punch mark on bottom surface. 60 degree crosshatch pattern on face. No tracks on either side of gear. |