Kollmorgen XM-21 Variation 3
Kollmorgen XM-21 Variation 3

The Army Weapons Command/Rock Island Arsenal 1967 M14 sniper scope system variation #3 with Kollmorgen 6X telescope saw extensive combat use during the early years of the Vietnam War and continued to see MACV-SOG combat use, mounted on M-21 rifles until the end of the Vietnam War in 1975.

This is one of 100 variation #3 units to be manufactured and issued in 1967 and is the only unit known to have survived due to heavy losses early in the Vietnam War.

  • Variation #1: M-84 2.2x 7/8" steel tube black oxide finished. At least 300 units manufactured, total manufactured unknown. Large knurled receiver screw. Griffin and Howe steel mount/ring assembly.
  • Variation: #2 M-84 2.2X 7/8" steel tube black oxide finished. 100 units manufactured. Either slotted or allen receiver screw. Griffin and Howe steel mount/ring assembly. 
  • Variation #3 Kollmorgen 6X 26mm 6061 aluminum alloy tube, green anodized finish, factory marked. 100 units manufactured. AWC/RIA steel bracket parkerized finish with either slotted or allen receiver mounting screw. Stamped USMC on both sides to differentiate from Army inventory. Griffin and Howe steel mount/ring assembly.

The Kollmorgen 6X was found superior over the M-84 for the following reasons:

  1. The Kollmorgen 6X magnification is superior to M-84 2.2 magnification.
  2. The adjustable objective is superior to the M-84 fixed objective as it corrects for reticle shift parallax and allows for focus.
  3. The Kollmorgen field of view at 100 yards of 20' is superior to the M-84 view of 42' as it provides for improved target identification contrast over background.
  4. The Kollmorgen 1/2 MOA elevation and windage adjustments are superior to the M-84 1 MOA adjustments. 5) The Kollmorgen light transmission of 86% is superior to the M-84 light transmission of 76%.