Chrome Projectile 7.92x57


#1

I’m trying to identify a 7.92x57 cartridge which has a chromed magnetic boattail projectile with exposed lead at the base. The headstamp is Z VI 19 38 (12,6,9,3 o’clock) with lines separating. Believed to be manufactured by Zbrojovka Brno, in Brno Czechoslovakia. The brass case has a berdan primer with a central flash hole rather than the holes usually seen. Is this type of primer unusual? Can anyone identify this type of projectile? Thanks, Tom


#2

Could you give us a bit more detail on this? How does it work? Are you sure is not just a single flash hole (but offset) as opposed to the usual two? Single flash holes were not uncommon with berdan primers but more likely to to be found on pistol cases. Its the idea of it being central I am struggling to visualise.


#3

Some Czech cartridges had a Berdan primer pocket with an integral anvil but the anvil was pierced with a central flash hole rather than the more common flash holes around the anvil.

gravelbelly


#4

[quote=“gravelbelly”]Some Czech cartridges had a Berdan primer pocket with an integral anvil but the anvil was pierced with a central flash hole rather than the more common flash holes around the anvil.

gravelbelly[/quote]
Well I have learned something new there. Surely that would make manufacture of the case more difficult with much more potential for rejects.


#5

The Czechs were happy with this design for years and this was the design of cartridge case which was in vogue when the UK adopted the Czech designed ZB37 machine gun which evolved into the BESA. Peter Labbett studied this adoption in some detail and published a “Technical Ammunition Guide” on the 7.92mm BESA in UK service.

gravelbelly


#6

hkp7m8–The chromed bullet jacket on Czech s.S. heavy BT ball (Model 1934) is standard for this load as made in in Czechoslovakia. It make it very easy to ID Czech made ball cartridges.


#7

The Czechoslovak Ammunition Industries (S&B Prague, S&B Vlasim, GR/JR Georg/ Jiri Roth-Bratislava>>“Circle M”>>>“Z” ( ZB ) Bratislava>>> Povaske Bystrica (Slovakia)…all used the Austrian G.Roth Patent primer system.
(ie, Berdan with a notched anvil and central flash hole primer Pocket.)

Used on all Czech-made ammo from 1919 to 1940, when German Technology was adopted ( Twin Flash, solid anvil Berdan, at least for the “German” style ammo…some of the “commerical S&B” etc was still made with the Roth System (for export, during WW II).

One aspect of the Roth system was that it allowed easy decapping (using a fine pin) and Depot reloading— esp. used by the Dutch 6,5x53R, by the Portuguese ( 8x56R Krop and .303, and 6,5x58P) by the Bulgarians and Austro-Hungarians ( 8x50R)…but was not adopted for the 8x56R M30 case.

By the end of the War, the Czechs concentrated on the Normal Berdan ( even with a single, offset hole) for all Postwar priming.

The Roth priming system is a unique system, in the (Berdan) priming world, and allowed for a larger anvil to be used, making ignition even more reliable (greater impact surface area);

Too bad that Strategic/Industrial considerations during WW II overruled its general use.

The Demise of the Roth System also saw the early demise of the 5,0mm Primer ( ie, .199") for rifle use, although this size has remained for “Large Calibre Pistol” Berdan in Central and Southern Europe ( .45ACP, 7,62 Tok, etc.

Regards,
Doc AV
AV Ballistics.
PS, I have a Roth Decapping and FLS Dies set for 8x50R (custom made in Australia by a now-deceased die maker) and I use it regularly on “Circle M” cases ( Czech. made-Bulgarian 8x50R cases, 1935)
and I made a similar set for (military) 6,5 Dutch as well. Just that .199 primers are rare these days ( RWS #5005–Pistol cup).


#8

I wonder if Doc or someone else could cite a documentary source identifying the Berdan central flashhole primer pocket adopted with, it appears, the 8 x 50R Mannlicher cartridge in 1888? Last night I read Moetz vol. 1 as far as my limited German would permit and found that he only described this as an “Einloch-Berdanzuendung,” or “single flashhole Berdan primer.” He does, of course, show and describe early Austrian center fire military cartridges employing the “Roth-patent” primer which certainly is conceptually similar to the 1888 design. Perhaps Moetz addresses this in his vol. 2 (which I haven’t seen). Jack