MODERN BRASS CASE TYPES
Basic cartridge case forms include the following variations L. To R. Straight-walled rimmed (45-70); straight-tapered (38-55); rimmed-bottleneck (30-40 Krag); straight semi-rimmed (351 Winchester SL, now obsolete); straight rimless (30 Carbine); semi-rimmed bottleneck (220 Swift); rimless bottleneck (30-06); rebated head (.284 Winchester); straight belted (458 Mag); and bottleneck belted (Weatherby 7mm Mag).
As firearms technology has advanced, guns have become more powerful and sophisticated. Cartridge case design has had to keep pace with this evolution. In reality, cartridges are often designed first and then guns are designed or adapted to fit them.
The basic design of contemporary centerfire cartridge cases include some of the following variations:
1) Straight walled rimmed. These date from the 19th century. They include the 32 and 38 S&W revolver cartridges, the 45 Long Colt and the 45-70 rifle. They also include modern cartridges such as the 38 Special, 357 Magnum and 44 Magnum revolver cartridges.
2) Straight-tapered. An effort to improve extraction led to this design. It is now nearly obsolete, the 38-55 being the only current survivor.
3) Rimmed bottleneck. These include late 19th century smokeless powder cartridges such as the 30-30 and 30-40 , 303 British, and .22 Hornet.
4) Semi-rimmed straight. These include currently made 32 Auto and 38 Super Automatic cartridges. The semi-rimmed design was to facilitate feeding through box magazines, with a slight rim to keep the cartridge from entering the chamber.
5) Semi-rimless bottleneck. Now rare, the 220 Swift is an example.
6) Rimless-straight. A common example is the 45 Colt automatic.
7) Rimless-tapered. These incude the 9mm Luger and 30 M-1 carbine.
8) Rimless-bottleneck. This is an improved smokeless design from the 1890′s. Most modern rifle cartridges use this design.
9) Rimless belted. This design is used only on high-pressure magnum rifle cartridges such as the 458 Winchester Magnum.
10) Rebated head. This case features a rimless head smaller than the body permitting a slightly increased case capacity. Examples include the 284 Winchester rifle and 41 and 50 Action Express cartridges.
When buying cartridge cases for reloading, the first thing you want to be sure of is that you have the right one for your gun. Most civilian guns are marked on the barrel regarding the ammunition to be used in it. Military arms, however, are not, or at least not very often. When in doubt, check it out with a good gunsmith. If there is no question about caliber, you want to get new or once-fired cases from a reputable source — marked with the headstamp of a known manufacturer and not from the “Royal Elbonian Arsenal.” Military cases referred to collectively as “brass” are often sold at bargain prices.
What headstamps tell you. Commercial ammunition is marked with the caliber and name of the manufacturer, at least in this country. Military ammunition is stamped with the code of the arsenal or manufacturer and the date of manufacture. Top, L. To R. 45-70 current head stamp; pre WWII commercial Winchester and Remington head stamps – good candidates for being mercuric primed; inside-primed military centerfire from the 1870′s and 80′s. “R” indicates a rifle load, “F” is the code of the Frankford Arsenal, “2 82″ indicates it was loaded in February 1882. Bottom, (left) a Frankford Arsenal round loaded February, 1904. Right, Spencer 52 cal rimfire was made by the Sage Ammunition Works.
Sometimes they are a bargain if they are fired only once and are not battered up by being run through a machine gun. The best military ammunition bargains are loaded ammunition. That way you get to shoot it first. Military cases do, however, have a few drawbacks. Assuming they are not Berdan primed, they may have been fired with corrosive primers. A wash in hot water and detergent will remove corrosive primer salts after firing.
The main problem with military cases is the crimp holding in the primer. Removing this crimp means a heavy-duty decapping pin and either chamfering the primer pocket or removing the crimp with a primer-pocket swage die, as explained in the chapter “Reloading Rifle Cartridges.”
With the exception of new unfired cases in the box, all cases should be given an initial inspection. Bulk, once-fired, military and commercial cases may have loose debris including primers (live and dead) rattling around inside them that should be removed. Cases should be sorted by manufacturer and kept in separate containers. Although the dimensions for all cases of a particular caliber are basically the same, internal dimensions (caused by varying wall thickness and head thickness) and the size of the vent in the primer pocket will vary. This will yield different pressures and velocities.
Mixed cases will thus give less accurate shooting. Varying pressures can be dangerous if the load you are using is a maximum one. If for instance this load is worked up using one type of case with a fairly thin wall and thus a comparatively large internal capacity, in combination with a small vent, the internal pressure will be significantly lower than one with a thicker wall, smaller capacity and larger vent.
Beyond separation by manufacturer, cases should be checked for splits in the neck, heavy corrosion and any anomalies indicating pressure or headspace problems or serious battering in the firing process, such as seriously damaged necks, that would render them unreloadable. Oil, grease, grit and dirt should be removed before reloading.
The headstamp markings of cartridge cases contain valuable information that will prove useful in buying ammunition and brass cases. Commercial manufacturers mark their cases with their name or trade mark, the caliber of the cartridge and the name of the cartridge, e.g., WW 45-70 Govt. This tells you it was made by Winchester/Western and it is the 45-70 Government cartridge originally made for the 45 caliber Springfield army rifle.
Markings on cartridge cases made for the military contain similar information, plus a two-digit date of manufacture.
L C is the Lake City Ordnance Plant. W R A is Winchester Repeating Arms Company. R A is Remington Arms Company. A stamp of R A 79 indicates the cartridge was made by Remington in 1979. American military cases are not marked by caliber. Early cartridges made in the Frankford Arsenal in Philadelphia were marked F or FA 3 05. This indicates the source and the month of manufacture (March) and the year 1905.
This is not ammunition you would want to shoot, especially if it shows any sign of corrosion. American-made military ammunition used corrosive priming into the early 1950′s. Different arsenals switched to non-corrosive priming at different times with all being changed over by 1954. Non-corrosive priming will require less cleaning of your gun.
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About the Author: C. RODNEY JAMES has been a shooter and reloader for more than forty years. Rodney’s technical and historical articles have appeared in Gun Digest, Handloader's Digest, Guns Illustrated, Shooter's Bible, Guns Magazine and AFTE Journal, the publication of the Association of Firearm and Tool Mark Examiners. He is the author of the 6th and 9th Editions of The ABCs of Reloading.
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