: I'm wondering if anyone know how i might find
: more information/history/photos on this
: movement that is in my AT Railmaster
: 2503.52. I know it's a comparatively simple
: movement with no complications but that's
: just one reason of many that i chose this
: particular watch. I also know it has none of
: the electromagnetic shielding that was
: featured on the original movement. I was
: also wondering if it's related to any of the
: 2500 derivations. I do like the cool display
: back but i was just curious to see if anyone
: had anything else on it. I have come up
: empty on TZ and Google in general. Thanks!
The link below, taken from this website, has some interesting comparison info between the current and vintage Railmasters.
As to your question about the 2403 movement, it is simply caliber 2500 without a date feature. However, you'll note that it is caliber 2403A, which is what all of the current Railmasters use. 2403A has the same beat rate as the older version of caliber 2500 (2500B). These movements vibrate at 8 beats per second (28,800 beats per hour). The newer version of caliber 2500 is caliber 2500C, which is in all Planet Oceans and newer production Aqua Terras and DeVilles. This version has a slower beat rate (7 beats per second, or 25,200 beats per hour). This gives the watch about an extra 3.5 hours of power reserve since the watch isn't beating as fast. I'm not sure if Omega will update caliber 2403 in the future.
