Yesterday's Weapons Forums

Don't know if this is the place to put this or if any one is really interested but have been trying to get my cartridge collection on disks to help reduce the pile of notebooks it has turned into. Copied these and thought they were unusual enough to post. Top photo is of experimental .30 cal. very high velocity rounds. 50 cal. cases neck to .30 M1 ball. From what I have found in reading documents from Frankford Arsenal the top 2 with the square shoulders all ruptured and by the time they got them to work the project was dropped. Have yet to find documentation as to what the were trying to do or why they stopped the development. The picture isn't real clear but the cross section shows that they used 2 different grain sizes of powder fine at the primer to heavy.
2nd. picture is of a set of shrapnel test cartridges from .22 rimfire to the big 50. Picture agin is less than great bit the projectiles are all different shapes to imitate shrapnel fragments for what ever they were testing.
All are from WW2.

Very interesting!!! Elmer Keith wrote of experimental cartridges like this. He claimed he made them up with a tube threaded into the primer pocket. The tube was filled with BP. When the primer popped, the BP in the tube ignited the powder at the front of the cartridge which was meant to lessen bore erosion among other things. SW

interesting , but im not a cartrige collector , i will monitor to see what i can learn

I haven't seen the stuff from Mr. Keith, will have to look that up thanks. I do however have a number of different cal. bore erosion test rounds. These were made to increase the erosive effects of each round fired by I think a 100(would have to double check notes on that) this was done to test how many rounds a barrel could take prior to burnout. I'll go through what I have and try to post them, they are strange looking.

Thank you A square 10, cartridges are one of my many weaknesses (8600 and still counting, started when I was 10 or 11) along with US military firearms prior to 1960, old pocket pistols, edged weapons, stone artifacts, and what ever might catch my fancy. (No wonder I never seem to have any money in my pocket.((thank god for an understanding and probably long suffering wife)))

One of the Central European countries had used a cartridge similar to the necked down cartridges shown for an ultra high velocity armor piercing application.
It was a 7.92 bore weapon with the parent case based on the WW2 German .50 caliber anti tank rifle cartridge.

The weapon was effective against some early light tanks and halftracks or armored cars, but useless against the majority of tanks used during WW2.

I am thinking that the Germans had an 8mm with about a 100mm case back around WW2.

Rad

php3YSrQePM.jpg [ 41.31 KiB | Viewed 5001 times ]

php3YSrQePM.jpg [ 41.31 KiB | Viewed 5001 times ]
You are correct HerrMesser. The German army did field a antitank rifle(cartridge pic. one) as did the english and the russians. The US also had one but I do not know if it ever went into the field as the others did.
The germans soon when to the PAC artillery(pic. 2 1940 issue) finding the rifle round lacking with newer armor.

The Germans found a better method of obtaining ultra high velocities by using the Squeeze bore priciple.
The squeeze bore guns used a tapered section of bore and a deformable skirt and/or driving band to reduce the area of the base of the projectile as it traveled up the bore. Reducing the area meant increasingly improved efficiency of the gas column which would otherwise have slackened off in its ability to accelerate the projectile as the length of the column of propellent gases increased.

The principle was applied to sporting rifles in a small way, but didn't lend itself to that application. The rather modest increases in velocity of bullets in the sporting rifle class and limited by the allowable weight of sporting rifle barrels resulted in diminishing returns.
Increaed velocity for sporting rifles was more easily acheived by increased powder capacity, longer barrels, and improved propellents.
The Squeeze bore would make better use of propellents but such savings would not be worth the initial expense and complication.

The squeeze bore was applied to some experimental small arms in the 60's and 70's, some using multiple projectiles but nothing came of it.
These mainly were intended to swage a stack of short projectiles into a swarm of longer and smaller diameter projectiles to give better penetration and range.

The tapered bore has been tested starting in the '20's and has been in some form of development at lest through the late '80's, the cartridges in the picture are all from tests at Frankford Arsenal during the second world war and were based on the German Gerlich work.

This
http://en.wikipedia.org/wiki/2.8_cm_sPzB_41
Was about the smallest of the anti-tank rifles built on the Squeeze bore principle, at least the smallest sucessful version.
It weighed in at well over 20 pounds, so it was not easily deployed by an individual operator as the British Boys rifle and earlier German anti tank rifles had been, but was far more effective against lightly armoreed vehicles.

The U S attempted to apply the principle to their 37mm anti tank guns, but the taper bore section quickly deformed in use, rendering the gun unusable.
The British used an add on adapter called the Little John to increase muzzle velocity of their 2 pounder tank gun.

Heres the .wz35 the Polish anti tank rifle I spoke of earlier.
http://en.wikipedia.org/wiki/Anti-tank_rifle,_model_35
Velocity of its 7.9mm bullet was in the neighborhood of 4,000 FPS give of take a few.
The bullet was not of the common steel or tungsten core type, but rather a heavy lead core in a thick steel jacket. Rather than penetrating the armor plate it transfered enough energy in a small area that a hunk of the armor plating larger than the bullet was broken loose from the inside surface at high velocity to do the damage to men or machinery.

Very heavy, short ranged, short barrel life, low armor penetration, and other problems like heavy barrel fouling it is no wonder shoulder fired anti-tank rockets were developed instead.

good to have if a half track with MG protected by a gunshield is chewing up your men.