Canadian Bren Blank Adapter - Steel notation translation?

[WallyG.]

Peter:

I have a 1945 drawing for the Canadian style BFA (.303 short blank)... the choke is specified to be made from "O.E. 154 GR. 2" and the muzzle attachment is specified to be made from "O.E. 136"

Is it possible to translate these steel grade notations into a "modern" equivalent that my US machinist will recognize? Thanks for any assistance you may be able to provide.

Information

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[Peter Laidler]

Anyone got an old copy of Machinerys Handbook handy? That will cross reference it. I bet JMoore will have one handy!

[WallyG.]

Thanks for the lead... I find versions back to the 25th edition with a quick search... how many editions back are you thinking one must go to find this information?

---------- Post added at 09:50 AM ---------- Previous post was at 09:46 AM ----------

Do you recall what the abbreviation "O.E." represents... Could it be as simple as "Original Equipment" as commonly seen in references to vintage auto parts?

[Peter Laidler]

I think it'll be from the 50's. I'm not a metallurgist (although I was in a metallurgy lab at Portsmouth today.....) but I think the 254 and 136 indicate the hardness spec and GP2 is Group 2. Mind you, the steel pegs at the breech end don't have to be hard - or even tough come to that - as they just have to prevent a full-length round (or a bulletted blank) from being fed into the chamber.

I have a funny feeling from our old EMER's from the original EMER library that these two stop pins at the chamber end were a later modification to prevent the insertion of a live round (and subsequent locking up enabling it to fire!) I realise that the magazine insert will prevent this but you've got to cater for the platoon know-all. I don't ever recall these short blanks being used in UK service but it must have been looked into for a provisional EMER to have been produced. Sorry to go off the subject............

[Warren]

Short blanks were used in Canada along with the two pins in the barrel as well as the magazine insert for the short blanks. The entire set up came in a wooden box and the early barrels are RED in colour....later to be painted yellow to conform to NATO standards. You will still find the odd red barrel around with the cylindrical screw on type BFA