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105mm Shot from APDS-T question

bacarnal

bacarnal

Ordnance Approved/Premium
Ordnance approved
Digging in my gun room and found a couple of shot for the 105mm APDS-T. The question that I have is this; The shot with the rounded nose weighs close enough to 7pds 6.8ozs or 3.375kg. The other came in at 5lbs 14.8oz or 2.693kg. The nick out of the base of the damaged one should only account for a couple of ounces. They aren't that different in height 5.900" vs. 5.742". Why is there such a weight disparity? Does anyone know of any different compositions or models? Any help would be appreciated. Thanks, Bruce.

P9241471.JPGP9241472.JPG
 
Bruce,

All of the Tungsten that you find is most likely made from powdered metal, and sintered. Tungsten has such a high melting point, that it is very rarely melted. It has the highest melting point of any metal, above 6,100 degrees F. Everyone that uses tungsten whether it be inserts for machine tools, penetrators, or even counterweights etc. specifies the exact mix or tungsten powder with other powdered elements to get the characteristics they want. Machine tool inserts will be an alloy of tungsten, carbon, and other elements to give it toughness and heat and wear resistance, typically called Tungsten Carbide. Penetrator customers will want their alloy to be shock resistant to withstand the impact on the target without shattering.

If you have a friend with a mass spectrometer, you could have your samples analyzed for elemental composition, but good luck trying to get a sample chipped off, and trying to get the sample to melt.
 
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Just curious, could one be the penetrator core from a 105MM tactical APDS-T projectile and the other from a TPDS-T like a M737, possibly with the same size and profile but made from different materials?

Jason
 
Jason, The core to the M724/M737 is aluminum sitting in a steel base. Found many of those on the ranges and my last job.

John, I see where you're going. The core on the right is magnetic, so it would be Tungsten Carbide, or the Tungsten/Nickle/Copper as give in the TM 43-0001-28. The one on the left has no magnetic properties, so (maybe) is pure tungsten. Thanks, Bruce.
 
Bruce,

The only metal that is magnetic has to contain iron. Tungsten carbide is W2C, no iron. I'm thinking your light one is either steel or made from powdered iron/steel and tungsten.
 
Try a hacksaw on a discrete part. It may cut one and not the other.
I once removed a 17 pounder from a relic sheath and the hacksaw didn't touch the core, presumably its tungsten carbide on the 17 pounder.
I tried the same on a 105 and the hacksaw bit right into the tungsten alloy.
Dave.
 
John, Nickel and cobalt are also magnetic, plus some other rare earth metals, so it's the nickel in it that draws the magnet.

Dave, Tried the hacksaw into them. The less dense one bites somewhat and the denser one didn't do anything. Thanks, all, Bruce.
 
Bruce,

I had a carbide burr for use in a die grinder sitting around on my desk. Tried a magnet on it, and it was very slightly magnetic.
 
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