.50 Headstamp RO


Can anyone please help me with a headstamp on a .50 cal/12.7 x 99

The Headstamp is RO 95 the round is a API Tracer with Red over Silver tip

also when is a round a .50 cal or 12.7 x 99mm.



From Ron Fuchs’ excellent 50BMG info guide:
RO 95 was made in the Netherlands by Eurometal under contract for British Aerospace Royal Ordnance division. The red over silver tip is a 606gr M20 APIT bullet. They made both APIT and API rds with this headstamp. Berdan primed.


Rich–As to when a round is a .50 Cal BMG or a 12.7 x 99, it depends on where it was made. They are the same cartridge, but the designation depends if it was made in a country using inch measurement or in a country using the metric system.


Many thanks am I correct in cataloging this round as a 12.7 x 99 then as both the Netherlands “manufacturer” and the UK “buyer” both were metric in 1995 when these rounds were made.



Rich–It is up to you. Technically it is a 12.7 x 99, but, at least for myself, unless the headstamp itself includes “12.7” or “12.7 x 99” I catalog them all as .50 BMG.


many thanks,