A little confused here John. If it only lasted 20 years, why wouldn't it be obsolete? Just an oversight, or do you know of a company still offering this ammo newly made? I've never found any for sale in my searches?

Vall the journey for the 9.5x47R (typo error of 9.15x47R) started with a beautiful Schuetzen rifle that I bought off the forum For Sale.  Not a clue as to it's caliber - posted a chamber cast - a member had a 9.5x47R rifle and provided loading data - one of the members found the bullet picture in an old German Bullet collector catalog - I had Accurate Molds do a  clone of the bullet - over a 2 year period found all the Bertram cases available for sale -

interesting JB, thanks for sharing.

Was Bertram once a cartridge manufacturer or always one of just obsolete and hard to find brass. Does anyone happen to know how, when and why they first got started and what prompted them to get into the business. In doing a search it only speaks of it as being a new company and does not list any obsolete brass that I could find but basically more modern brass.

Apart from .22LR, all my cartridge rifles are in calibres on the UK obolete list, with the exception of my 44-40 Winchester '92.
To be included on the list, the amunition has to be out of production and the government has to believe that there remain little or no stocks of the ammo.
Some of the calibres on the list are easy for an experienced reloader to manufacture, for example, 44 Russion. Others are more difficult and, if you want to add an obsolete calibre to your FAC and shoot it, Betram brass is usually the only way to go.
I have Bertram brass in 300 Sherwood, ,43 Mauser and I used to have 300 Rook.
It is worth mentioning that the UK cut off date for antiques, and this includes the obsolete calibres, is 1939. You cannot for example buy or own a Pedersoli sharps in 50-90 but, providing that you do not want to shoot it, an original is antique and obsolete and can be bought by any person over the age of 18 who does not have a criminal record.
Fred