Quick answer
The Omega Speedmaster 323.10.44.51.01.001 is a 44.25 mm steel Moonphase Master Chronometer. Counterfeits of this exact reference are less common than fake Moonwatch Professionals, so a seller may hand you a lower-grade replica dressed in the right box. Confirm four things before money changes hands: a 44.25 mm case, a calibre 9904 movement behind a sapphire back, crisp dial print, and matching serials on case, movement, and warranty card.
omega speedmaster 323.10.44 counterfeit
Prerequisites
- Digital calipers with 0.01 mm resolution
- 10x jeweler loupe
- Bright, adjustable desk lamp
- Reference photos of 323.10.44.51.01.001 from official Omega material
- Access to a watchmaker with a timing machine
Step-by-step inspection
- Request the full reference number and photos of the caseback and movement before you meet the seller.
- Measure the case across the 9 to 3 line with calipers, crown and pushers excluded, and confirm 44.25 mm.
- Set the watch under the lamp and inspect dial text with the loupe for sharp edges and ink bleed.
- Check the applied logo and hour markers under raking light; all should sit level in one plane.
- Examine the moonphase aperture and confirm a photographic moon image rather than a flat cartoon disc.
- Study the tachymeter scale on the bezel for filled markings that sit flush with no paint overrun.
- Turn the watch over and judge the depth and edge quality of the caseback engraving and hippocampus.
- Press the pushers and start the chronograph, then reset; hands should return to zero with a firm snap.
- Look through the sapphire back for calibre 9904 with a co-axial escapement, free-sprung balance, and silicon hairspring.
- Inspect the bracelet for screw-fitted links, tight end link fit, and a cleanly engraved clasp logo.
- Compare the serial on the caseback with the movement bridge and the warranty card; all three must agree.
- Hand the watch to a watchmaker for a timing machine reading and a rate check in several positions.
Red flags
- A price far below the going rate for a used steel moonphase.
- Seller refuses movement photos or a watchmaker inspection.
- Subdial spacing that looks crowded, a sign of a stock chronograph base movement inside.
- A date that crawls into place over several hours instead of changing at midnight.
- Box and papers with a serial that does not match the case.
- Case thickness above the genuine profile, caused by a thicker third-party movement.
Final check
A genuine 323.10.44.51.01.001 carries Master Chronometer certification, so the movement should pass a METAS-style test for rate and magnetic resistance. If the seller cannot produce a documented service history or allow an independent inspection, walk away. Paperwork and a watchmaker's report carry more weight than any single visual detail.