.50 Browning Headstamp with stars


#1

I have a 0.50 Browning ball M2 (I think).
What mean the stars on the headstamp ?

Michel


#2

Maverick - I have acquired an answer to your question from Woodin Laboratory, thru the good offices of Colonel Frank Hackley, USA (Retired), who was the last Commanding Officer of Frankford Arsenal. I will simply quote exactly what he sent me, since I am totally unqualified to add anything of my own to the discussion:

 "During 1949-1950 the Frankford Arsenal Industrial Division issued a number of requests to corporations for

Manufacturing Methods & Technology (MM&T) proposals to reduce the cost and increase the productivity for small arms ammunition manufacturing. In response, a proposal was submitted by Olin Industries (Winchester) in 1950 from their internal project to make .50 brass cases by impact extrusion and that same year they submitted to the Arsenal a 10,000 round lot of Cal. .50 Ball M2 cartridges with extruded cases for test and evaluation. These rounds were identified by a special headstamp W.R.A. star 50 star and used a bluish 4-dot primer seal then in use by Winchester for .50 contracts. During our research for Vol. III, no Frankford Arsenal test report for this lot could be located and it is assumed the results were not completely satisfactory?

 "It appears the photo of the round posted is from the test lot with extruded case."

Courtesy of Woodin Laboratory, Tucson, Arizona.


#3

I don’t mean to sound dumb but I am ignorant of the process by which ‘regular’ brass cases are made if “impact extrusion” is something special. What makes impact extrusion different?


#4

Normal Cartridge “Drawing” method starts with a Disc of brass punched from a Strip of Rolled brass, then it is Cupped, then Drawn and Ironed ( Lengthened and the walls thinned, till a long deep cup is obtained.) This is then “Headed” ( head flattened, Primer pocket formed, and headstamped) Trimmed( to length and head extractor Groove lathe cut) and then “Tapered and formed” ( body taper applied, Neck and shoulder formed.)

The Impact Extrusion method is similar to the way Soda ( Coke) Cans are made from Aluminium.
The first "Extrusion " method was invented by Hooker, during or before WW I (Tried by USCCo. in 1918 for Aircraft .30/06 cases ( USCco 18, two stars)…
The Brass is “headed” from a slug of Thick brass wire,or thick sheet into a Cup formed like an inverted top hat, with a large thick rim at the mouth. This rim is pressed between two Dies and a ram so that the Brass is extruded out into the longer cup tube, until the final length is achieved. After trimming to length, the normal forming up processes are used (Heading, trimming. head cutting, etc)
The Die making is more complicated than normal “deep drawing” method,
And Higher Extrusion pressures are required ( Usually Hydraulic, rather than mechanical) Hence the process is slower, and higher in Tool cost.
( for Aluminium, being a softer metal, it is the ideal method of forming Tubes, Sections, etc, whether Cans or Engineering/structural Profiles).

In 1918-19, problems in the “flow” of the brass and resultant grain
structure resulted in head failures, a disastrous consequence in an Airborne (Remote) Guns. So the Hooker method was abandoned by the early 20s, at least for brass cases. With Aluminium, it came into its own with the development of the Aluminium, one piece- body Soda and Beer cans in the 1970s, after many years of the three-piece, rolled steel can ( and a brief interlude of extruded Steel cans (1960s-1980s). The Beer and Soda can collectors can enlighten us on these Canology developments.

Probably Winchester resurrected the Hooker method or an improvement there-of, for making .50 cases…hence the “Two Star” indication…similar to the original USCCo marking, and probably the same QA problems arose as well. Or just the cost factor cut in as well.

Just as the USCCo ammo was then down graded to ground use at the end of WW I, the Trial Lot of WRA ammo probably ended up the same way. And being marked in a “Export” manner, could have been sold off to some (LatinAmerican) Country which used .50 BMGs ( usually the Watercooled version )… similar marked (Non-starred) .50 ammo was supplied by WRA to Argentina etc, which had Naval .50 WCBMG…Just thinking…

Check with the Woodin Lab about the History of the Hooker brass extrusion method.

Regards,
Doc AV
AV Ballistics.


#5

Thanks for all the great information.

Michel


#6

Further use of impact extrusion was by Speer for his failed Weatherby contract also it was used in manufacture of the Newton, and Watts cases by Speer.

Currently from what I understand most of the current L.C. .223/5.56 is with a variation of the extrusion method and (most ??? if not all ???) CCI / Speer product is also now by that method. A big advantage is waste, very, very little compared to drawing. (little to recycle & handle).


#7

Thank you for the education Doc. I’ve copied and filed.