I picked up an odd .30-'06 empty at the range yesterday. Brass-cased and Boxer-primed with a two-leg primer anvil, it had an annular groove around the primer similar to the one found on 8mm Lebel rounds, but not as deep. The case head design matched a pile of French (“SF 71”) 7.62mm NATO empties nearby. The kicker was the headstamp: “R” and “A” at 11 and 1 o’clock, respectively, and “43” at 6 o’clock. Did Remington make .30-'06 for the Free French to their specifications and if so, why?
A photo would help. Or, a better description of what you mean by “annular groove . . .similar to . . . 8mm Lebel rounds” and “case head design”.
I’ll try to get a photo posted. The 8mm Lebel had a groove around the primer so that the point of the following bullet would ride it that instead of on the primer and so prevent detonations in the Lebel’s tubular magazine. The 7.62mm NATO cases I found had the same annular groove as the .30-'06 case. I don’t think this is a relic of the crimpimg process since it is well outside the primer pocket.
Probably don’t need a photo for this one. what you have is a very commmon Remington form of heavy primer crimp, applied on military ammunition after encountering problems with primers blowing out in certain types of weapons. The problem was addressed in late 1917. Various crimping methods using different numbers of stab crimps, three or six, were tried and the very heavy crimp of your round was the end solution. It was used until 1945, and I don’t recall seeing it on anything but Remington and U.S.C.Co-made .30-06, although others may have used it. Much G.I. .30-06 ammunition has primers held in by a circular crimp, but this style is much heavier than the norm.
I have heard it referred to as a crimp for aircraft machine guns. This may be true, in that they may have been among the weapons to blow primers, but it was not made exclusively for this use. This crimp was even used on ammunition made for England and headstamped with the “300 Z” British-style caliber marking.
Reference: Who else? Chris Punnett’s fine book “30-06.”
For some simular headstamps see:
What John said.
These cartridges are common. Even the WW I ones are seen quite often.
I think there may be something to the idea that they were originally made for aircraft use. Since there is no way for a pilot to clear a jammed sychronized MG, extra precautions needed to be taken to ensure that primers did not blow. Those planes with a gunner did not need such a thing, of course.
pbutler: That’s exactly what I have.
Thanks for the quick reponses, guys.
The extra impressed groove in .30/06 from 1917 onwards was an expedient used to strengthen the head of the .30/06 case to be used in Aircraft MG ammo. The groove was NOT a “crimp”, but a means of Hardening the head further than what was required for normal “land” Ball. The Idea was developed by the Italians in 1895, after experiences with Case head expansion ( and subsequent primer Pocket Leakage). The Italians used this in all subsequent Carcano ammo.
The Italians matched this modification of the cartridge head to a groove in the Bolt head, so that the Bolt face actually “crimped” the primer in place when the cartridge was fired. The problem of leaky primers and swolen pockets was eliminated. ( no further crimping was used on the Primers, also because as a matter of course, Carcano cases were (at least prior to WW I),
“Re-capped” ( re-manufactured) when the primers were considered “life expired”; secondly, 6,5 Carcano was hardly ever used for Aircraft ( they preferred the Lewis , the Maxim, and the Captured Austrian Schwarzelose guns, all “stripped for Airservice”.
The ammo (.30 cal) with such a ring impression, was also Pocket crimped as well (I have USCo. cases from 1917 and 18 with three and six stab crimps in the inner ring, to lock in the Primer.
.300z ammo THis was a Remington British Contract (Pre-Lend lease), to accompany the many US aircraft with .30 Browning ANM2 guns being bought by Britain pre- Pearl Harbour.
The Packet label of this (and other US used ammo) with the “ring” was “AN-M2”, indicating specific use in Aircraft guns.
Now whether “AN” indicated “Army-Navy” ( universal use) or simply “AviatioN”
(preferred for Aircraft MGs) is a question asked by many. One thing is certain, AN-M2 guns were Only used in Aircraft because of their different construction and Rate of fire. When converted to ground use, problems occurred due to overheating and parts interchangeability with normal M1919A4 guns. An interesting USMC conversion of an AN-M2 for IwoJima use as an LMG (by a CMoH winner) was probably the fore-runner of the M1919A6 LMG (which used 1919A4 essentials)…see imas.nz.com for a photo and thread on this interesting Piece ( Garand Buttstock, BAR Bipod, ANM2 “works”, in the “machine gun” section.).
WE here in Australia have had quantities of this ammo (.300z) come out of Indonesia in the 1980s, as left overs from the Dutch use of it in the late 1940s, in ground guns ( still in White cotton belts) so it looks like after WW II, a lot of the “AN-M2” ammo was either downgraded or simply the .30 cal Aircraft Guns were no longer being used. ( Aircraft Browning ammo was almost always usually Steel Linked, but ammo was supplied in 20 round packets for “linking on the spot”.)
Synchronicity of US (export) ammo has always been a weak spot, and RAF rules make the ammo “not usable in synchronised guns” after about 12 months from manufacture.
The French forces also received a lot of .30/06 ammo during WW II, for the M17 rifles and BMGs in their Service from 1943 onwards ( North Aftrica, South of France, Normandy invasion, etc. When they did run out of US supplies etc, they made their own for over 20 years ( "Cartouche 7,62mm Modelle 1949 Balle "O’ ( “ordinaire”).
As to the use of the deep ring also in 7,5 MAS, it is assumed that this was an adaptation to ensure the correct hardness of the head of the case, especially since the French used the 7,5 also in fast firing Aircraft Guns during the 1930s (Darne and MAC designs).
Does all modern made commercial Carcano ammo also have the groove in the case head if there is a ring on the Carcano bolt head that fits this groove?
Sorry Falcon, obviously you have not examined closely a Carcano Bolt face.
There is no “ring” to match the case groove.
The Bolt face has a Groove running around the outer circumference of the cartridge recess, to allow any gas blowback to exit out of the gun safely. The resulting “raised section” of the Bolt face, which impinges on the Cartridge head, then acts like a “rivetting dolly” and will squeeze the inner ring of the Head of the case( that ridge of brass between the “groove” and the primer Pocket) in towards the primer cup, thus effectively sealing it off.
Non-Italian Carcano cases (Hirtenberger 1936, Winchester 1950s, Norma commercial, Prvi-Partizan commercial,) are made with Flat cartridge heads, as the brass is worked differently during heading up, and does not Need this “head groove”.
Probably a factor in this is that the HP1936 ammo used the .199 primer ( smaller than the round, .204 Italian primer, and with a narrower primer Pocket ( straight sided, rather than “flared,” as in the Italian cases); the Winchester cases used ?LR Boxer primers, ring crimped in place (normal US “Military” type procedure). And Prvi Partizan is a purely “sporting load” ( as is Norma, so no crimp applied at all…also LR Boxer.(.210).
So an 1890s “fix” continued in Italian service to the end of Italian Use and manufacture of 6,5 Carcano…probably even after the reason for it had disappeared with improved Cartridge head forming techniques…sort of like “if it ain’t broke, don’t fix it” attitude, or “we have always done it that way”…
One thing, it made cartridge headspace Bunters easier to make, the negative impression of the headstamp data was simple to engrave into the solid head former Punch. (to create the “relief” stampings.).
Funnily enough, the Italian 8x59 Breda cartridge was made in the same manner ( at least the brass cases were; I don’t know about Breda 8x59 Steel cases.).
Doc: my specimen of the Italian 8 m/m steel case has the typical annular groove around the primer pocket, but curiously in an article Charles Yust wrote on machine gun cartridges that looked like rifle rounds but weren’t he depicted–in one of his good sketches–an early headstamp (SMI 936 it seemed to be but the sketch was tiny) on an ordinary flat head. Evidently that one went by the board quickly. I’m sure he intended to depict a flat head because the sketch was paired with another headstamp having the groove. JG
DocAV, thanks for my explanation. Unfortunately, due to this country’s ridiculous gun laws, I have had very little opportunity to handle and examine any interesting firearms, nearly all of my firearms knowledge comes from books and the internet.