And the MO might sort you out a little TOO well: eating Cordite was a serious LMF issue (Lack of Moral Fibre) and was regarded as equal to an SIW (Self Inflicted Wound). You could be executed for either. Saying that a person would "eat Cordite" is a blatant accusation of cowardice; somebody ever says it to you, you are justified in decking the SOB RFN.
Ed, we had the TWO big plants turning the stuff out for the military, plus the ammo coming from the commercial factory, the Dominion Cartridge Company. The GOVERNMENT plant was the Dominion Arsenal (headstamp DA) and they stuck to the British specification: big corrosive/mercuric Berdan primer, Cordite loading and all that. Their ammo also was marked in British style, with the Type Letter (W for AP, B for Incendiary, G for Tracer and all those) as a part of the headstamp.
Defence Industries turned out the "generic" ammo, billions of rounds of it, all loaded with an IMR-type powder and with the smaller (.210") Boxer NCNM primers. This is where we started using bullet-tip colour codes ( as in US practice) for our Specials (anything other than Ball ammo), although our code was NOT the same as the US code. I have encountered orange, red, white and gray tips; NO tip code was Ball, pure and simple.
So the answer is "Yes": we did make both types of .303 ammo: Cordite and Extruded, corrosive and non, mercuric and non and they are easy to tell apart. DA stamp and big primer is the Cordite/corrosive stuff, DI stamp and regular primer is the NCNM. The "Z" in the headstamp is the POWDER CODE: C for Cordite, Z for extruded IMR-type (actually based on Nobel Neonite as it was made here).
Surplus powder of the type used in the DI ammo was sold by Higginson Powders into the 1980s as their Number 44 Powder. I had some and it was wonderful stuff although it flashed terribly with lightweight bullets; get the bullet weight up over 165 grains and the flash went away and your ammo was amazingly accurate if you did your end right. This is the powder with which my Ross started shooting single-ragged-hole groups off the sandbags. WISH I could source a few pounds more of the same stuff today! Oh well, we have IMR 4895 and 35 grains of that in the Ross, or 37 to 38 in the SMLE, gives just bout the same results in a good rifle with the Sierra 180 seated to the OAL of a Ball round (3.05").
Also, Ed, the US had a big batch of NCNM .30-06 that was made in Canada: headstamp VC 45. It was the only NCNM .30-'06 military ammo of World War II.
Hope this helps.
BTW, anyone have a DI-41 for sale or trade, any type? I have both 42s, 43, 44 and 45 and it would be nice to complete the set at last.