This is an ashtray I made 40+ years ago when I was stationed in West Germany. It's a brass casing from a 105mm (4.1+ inch) NATO-standard tank gun cartridge used in 105mm guns, such as those derived from the Royal Ordnance L7. It was probably fired in an M60A3 tank with an M68 105 mm tank gun. The M68 uses a British-designed L7 gun tube and cartridges with an American-designed mount, breech assembly and recoil mechanism. The same gun was used in M60, M60A1, and M1 tanks, before the M1A1 with the M256 120 mm smoothbore tank gun came out. The M1A1 uses a German-designed Rheinmetall Rh-120 L44 gun tube and combustible cartridges with an American-designed mount, cradle and recoil mechanism. I read that late versions of the M48 tank also used the M68 gun.
The recoiling gun mass is 2,487 lb, and the gun tube alone weighs 1,662 lb according to Wikipedia. That's one heavy barrel. I remember seeing the weight listed on the crate of a gun barrel my friends had to install. It was 1,600+ pounds but I can't remember exactly what it was after all this time. I thought it was more like 1,630 pounds. To change the barrel, you take the screws out that hold the bore evacuator on and remove it, take out 2 screws that hold the key in the keyway in the breechblock and remove it, turn the barrel 90 degrees CCW with a barrel wrench and pull it out. Put the new barrel in, turn it 90 degrees CW, fasten the key in the keyway, grease the area of the barrel where the bore evacuator fits, install the bore evacuator, and you're done. We had an overhead crane in the shop to pull the old barrel and put the replacement in, but I watched from a few feet away as it was being done in the field with a wrecker.
A bore evacuator or fume extractor is a device which removes lingering gases and airborne residues from the barrel of an armored fighting vehicle's gun after firing, particularly in tanks and self-propelled guns. By creating a pressure differential in the barrel after the shell leaves, the bore evacuator causes most of the propellant gases and combustion residues to exit via the muzzle. Thus, when the breech opens for reloading, those gases and residues do not escape into the crew compartment and pose a hazard to the gun crew. - Wikipedia.
I spent a couple hours sanding my ashtray and cleaning it up with steel wool before I took it up north to show some friends about a month ago. It's 1 13/16" long at the case mouth now, rather than 24.3" long. Until a couple weeks ago I didn't have a way to weigh it, but according to my new luggage scale, it weighs 5.1 pounds or 2.3 kilos. That's as fine as either scale gets, but either way, it's still over 5 pounds for a piece of brass that stands less that 2" tall, not including what's left of the primer. That brings it to 2.5" OAL as near as I can reckon, eyeballing across the primer with my tape measure in front of it.
The makings on the base of the shell are, 105MM M115, LOT NOR-5-2, 1961, and LS-81C006G008. It was made the year the Berlin Wall went up. Me too! Of all the 105mm shells I've seen, this was the only brass one. The rest were all steel, like the one I hung up that my friend and I used as a target several years ago. The case mouth was bent out of shape worse than dropping it off a tank would explain. I think it was run over by a jeep or other light truck. Once, when my roommates and I got a keg of beer, we didn't have a proper mallet to pound the taps in. But I had a 5 pound ashtray! Pounding the tap in the keg went okay, but when I pounded the vent down into the top of the keg, I pounded my friend's hand down into the keg too. Maybe that's why he won't return my email.
We used to get 50 liter kegs, 13.2 gallons of German DARK beer for 4 of us, so it didn't take long for his "narrow knuckles" to feel better. Or for none of us to feel anything from Friday after work through Sunday. I had a 3 liter stein and he had a 5 liter stein he called his shot glass. "You drink one of those, and you're shot."
It took about a case of beer just to fill these 2 steins once, hence the keg of beer. If we were going to haul beer down the block, and up all those stairs to our room at the top of the hangar, we'd rather just make one trip to the store.
In the first picture you can see how long the primer in one of these shells is. It doesn't ignite the powder at the base. It starts in the middle and spreads both ways to get the maximum burn. If it was like a regular small arms primer, it would probably blow unburnt powder out the muzzle and make an even bigger flash. The end of the primer had what amounts to a very large, slotted set screw screwed into the end of it. I unscrewed it and after I cut down the primer, and filed my cigarillo holder in the end, I filed the threads down on the screw, inverted it and pounded it into the unthreaded stub of the primer. It's beat up pretty bad but I think it turned out well for what I had to work with.
https://en.wikipedia.org/wiki/105%C3%97617mmR https://en.wikipedia.org/wiki/M68_(tank_gun)
https://en.wikipedia.org/wiki/Bore_evacuator