What calibre goes inside a ref 2506?

NT931 · Oct 13, 2018

I've been recently looking at Ref 2506, as it has a bigger case.

It struck me that
a) while the OVD says it should have cal 283 inside , and a well-known dealer had a 2506 for sale, also with a cal 283
b) forum members have shown their 2506 with a 30T2SC inside, and the same dealer also sold another 2506, with a 30T2SC.

So I'm a bit confused - could the Ref 2506 have, during it's production, have had either 30T2SC or cal 283 put in? (AFAIK, looking at the Ranfft database, cal 30T2SC and cal 283 are different, right?)

Any info appreciated, thanks!

heavenscloud · Oct 14, 2018

Yes, cal. 30 SC T2 and cal. 283 are different. According to AJTT, cal. 283 is 30 SC T3 PC AM 17 p and was created in 1949. OVD states that CK 2506 was introduced to the international collection in 1946 so watches prior to 1949 must have used a different caliber. I have a CK 2504 (35mm case) with cal. 280 (30 SC T2 PC AM 17 p created in 1941) and Extract confirming a 1949 production date. It seems reasonable that an early CK 2506 might have a cal. 30 SC T2 or cal. 280 even though that info is absent from OVD.

giotommaseo · Jan 22, 2019

... I have a 2506 from 1943 with a 30T2 SC caliber and one from 1949 with a 283 caliber...
... according to the Omega museum the caliber 30T2 SC was once ticking in a 2292 and around 1951/1952 was recased in a 2506...

Archer · Feb 7, 2019

055CK2506 | STEEL CASE CAL.283