Omega
Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00
The Omega Seamaster Railmaster Co-Axial Chronometer 39.2 (reference 2503.52.00) is a 39.2 mm stainless steel watch with a black dial. It runs on the automatic caliber 2500 with a 48-hour power reserve and is water resistant to 150 m. It is no longer in production.
Specifications
Case
- Reference
- 2503.52.00
- Collection
- Railmaster
- Case size
- 39.2 mm
- Case material
- Stainless steel
- Case shape
- Round
- Crystal
- Sapphire
- Water resistance
- 150 m
- Bracelet / strap
- Stainless steel bracelet
Dial and bezel
- Dial
- Black
Movement
- Movement
- Automatic
- Caliber
- 2500 (base ETA 2892-A2)
- Power reserve
- 48 hours
- Frequency
- 25,200 vph
- Jewels
- 27
- Functions
- Time only
Production
- Production
- Discontinued
How it compares within the Railmaster family
Side by side with other references in the same collection, from the catalog.
| Reference | Size | Material | Dial | Caliber | Years |
|---|---|---|---|---|---|
| 2503.52.00 (This watch) | 39.2 mm | Stainless steel | Black | 2500 | — |
| 220.10.38.20.01.002 | 38 mm | Stainless steel | Black | 8806 | 2017– |
| 220.10.40.20.01.001 | 40 mm | Stainless steel | Grey | 8806 | 2017– |
| 220.10.40.20.03.001 | 40 mm | Stainless steel | Blue | 8806 | — |
| 220.10.40.20.06.001 | 40 mm | Stainless steel | Grey | — | — |
| 220.12.40.20.03.001 | 40 mm | Stainless steel | Blue | 8806 | — |
| 235.10.38.20.06.001 | 38 mm | Stainless steel | Grey gradient | 8806 | 2025– |
| 235.10.38.20.13.001 | 38 mm | Stainless steel | — | — | — |
| 235.12.38.20.06.001 | 38 mm | Stainless steel | Grey gradient | — | — |
About the Railmaster family
The Railmaster was introduced in 1957 together with the Speedmaster and Seamaster 300 as part of Omega's trio of professional watches. It was built for people working near strong magnetic fields, such as railway workers and scientists, with a soft-iron inner case to protect the movement.
Omega revived the name in the 2000s with Co-Axial models and again in 2017, when a 40 mm Railmaster with the anti-magnetic Master Chronometer caliber 8806 brought back the simple vintage look with a textured dial. Later references in the catalog include smaller 38 mm versions. Dealers tell versions apart by size, dial texture and bracelet or strap.
Quick answers
- What size is the Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00?
- The Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00 has a 39.2 mm case.
- What movement does the Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00 use?
- It uses the automatic caliber 2500, with a 48-hour power reserve.
- How water resistant is the Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00?
- It is water resistant to 150 metres.
- Is the Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00 still in production?
- Discontinued.
- What is the Omega Seamaster Railmaster Co-Axial Chronometer 39.2 2503.52.00 made of?
- The case is stainless steel. Bracelet or strap: Stainless steel bracelet.
Catalog facts checked September 2026.