Editorial
Omega revived the calibre 321 in 2020 specifically for this reference, the first time the movement had been in production since 1968. At 39.7mm it wears smaller than the standard Moonwatch, and the sector dial and column-wheel chronograph give it a character the ETA/Sellita-era Speedmasters simply cannot match. If you want the historically correct Moonwatch movement in a new case, this is the only route.
The original cal 321 powered the Speedmaster through the Apollo missions before Omega replaced it with the cal 861 in 1968 for cost and reliability reasons. Omega reengineered the movement from scratch for the 60th anniversary launch in 2020, using a combination of reverse-engineering surviving examples and consulting with watchmakers who had worked on the original. The reference ships in two crystal variants: hesalite (ref. 311.30.40.30.01.001) faithful to the mission-era look, and sapphire crystal (311.30.40.30.01.002) for those who prioritize scratch resistance.
Both use the same case and movement; the hesalite version is generally considered the more historically coherent choice. Production has been steady since launch, with no major reference changes through 2026.
The cal 321 is a freshly produced movement but it is handwound, so inspect the crown and crown tube carefully, as forcing a wound-down crown is the most common user error. Check the chronograph operation through a full cycle: start, stop, and reset should all be crisp with no false starts or sluggish reset. The aluminum bezel insert on this reference will scratch; examine it under direct light for gouges or chips, since Omega's bezel inserts are not cheap to replace outside warranty.
At 50m water resistance this is not a tool watch, so look for evidence of crown-open exposure to moisture, particularly fogging on the hesalite crystal or condensation traces on the dial. Verify the sector dial printing is clean at the sub-register tracks, where any UV or chemical exposure shows as fading first.
