I had written this reply earlier in the day, but some glitch cancelled it before it was finished…anyway, here goes again, slightly reworded from memory.
Bulgaria entered WW II as a “Co-belligerant” of the Axis, but did not take part in any of the German foreign “invasions” such as the Russian Front. They were marginally involved in protecting rail connections with Germany proper (Bulgaria and Romania afforded Germany a Black Sea access, so that the German Navy could use E-boats and Italian MAS boats to attack the Russians at Sevastopol and other ports of the Black Sea Fleet. Entrance from the Mediterranean was closed by Turkey’s Neutrality.).
In 1938, Bulgaria received almost the totality of Austria’s inventory of M95/30 rifles in 8x56R, and large quantities of Ammo both from stock ( dating back to 1931) and new manufacture ( VIII-38 is the most common) from Hirtenberg ( now Factory P635 after the Anschluss of March 1938). At the same time, to increase production in Bulgaria (at Khazanlak, seen on the Label), the Germans passed on the technology to make Laquered steel cases ( Stahl/Stalina) for the “S” patronnyi (Bulgarian Nomenclature for the 8x56R with an “S” type projectile. Brass ammo is labelled 8mm Patronnyi “S” ( denoting 8x56R, whilst the older “8x50R” is denoted “Patronnyi 8mm mannlichera”…so an obvious advance to the Steel cased 8x56R is denoted “SS” Stalina patronnyi Kal 8mm S ( or simple “SS” on the packet…
…Nick, can you confirm this interpretation?
Furthermore, after 1941, Germany ceased large lot making 8x56R ( with either "letter codes or “P” codes, in German style) for use within Austria ( or “Ostmark” as the incorporated state was renamed); the Police usage was quite small, and capacity was required for 7,9 ammo.
In 1944, after Romania collapsed to the Russians, the Bulgarians expelled their King, and allowed the Russians to enter the country peacefully, and immediately undertook “assistance” of the Russians into Hungary and then Czechoslovakia.
The Local factories continued to make 8x56R as they had before, and by 1946, had begun making 7,62x54R, using “work in progress” brass of 8x56R origin, reformed to 7,62x54R ( headstamps seen on another board.) by the complete communization of the Bulgarian State( late 47-48, the factory became “10 *” ( 10 -five point star), and ammo was all brass manufacture for quite some time ( copper washed steel came in in the mid to late 50s).
With the Calibre changeover, the majority of 8x56R ammo in stock, some from 1936, was placed in sealed “strategic reserve” along with the M95/30 rifles (Variously called " Pushka &Karabina M95, Karabina M95/34, and Pushka M938 and M939, along with the LPM 39 ( a ZB30 in 8x56R) and other converted maxims and Schwarzloses, and Solothurn M30s; These were only surplussed off in the late 1980s; hence the flood of “Austrian” 8x56R in clips, and
packets or MG Tins of 8x56R in both brass and Steel, made in Bulgaria.
THis is the first time I have seen a 45 packed (but 44 dated) Steel 8x56R (left over work in progress?)
Other details on the label include the Charge weight (3.14 grams ==48.45 grains) the label says “Pushka & Karabina” (Rifle and Carbine) and the Powder (Barut) Lot 7…earlier Powder Lots indicated sources of Powder in Germany, Poland the Czechoslovakia, esp. before 1940.
Although the Charge weight indicates an “efficient” rifle Powder, earlier labelled lots show variation of Charge up to 58 grains, (MG Loose Pack) and 52 grains (Rifle/ MG Loose Pack)…By “Loose Pack” I mean a 250 round Zinc tin, with 10 round wrapped packets, NO clips. BTW, the MG type packs were labelled " Za Kartechnitza" ( Bulg. for machinegun) and occasionally "& Pushka/karabina ( and also rifle and carbine.)
So besides a variation of Powders used, there was a resultant differences in Powder weights, to maintain a standard ballistic specification…Ie, NO “different ammo” or “different (hotter)” Loadings, just the correct balance of Powder load to match the Powder type. ( almost all “Blattchen Pulver” --German Flake Powder).
I have not yet seen a 1945 Dated shell case,or a 1946 one ( unless one includes “converted” to brass 7,62x54R, probably a “preproduction” run.).
Some of the other Bulgarian Cartridge contributors (from Gunboards) may see this and contribute more info.
A sample of every Bulgarian 8x56R made from 36 to 44 (brass and steel as applicable) made by Dom Voenni Fabrika, Khazanlak ( “B phi Lion”).
PPS, as to Photos of Bulgarians in Action, see “The Eastern Front” a “coffee table” illustrated book by an English Author
who also did a lot of “Train” books, which has photos of Romanians & Italians and Germans as well as Bulgarians ( characteristic Helmet) with M95/30s and M939 LMG ( ZB 30B); Front unknown, but the short sleeves suggest summer, probably in the Balkans ( Partizan Policing duties)