M240
The M240 is the latest incarnation of the Belgian Mag 58 with some improvements. The US first adopted it as a replacement for the M219 co-ax gun on the M60A3 (RISE) tanks. We were just getting them when I left the service. I learned to take it apart, but left before we had any come in to the shop for repair. Considering one demonstration I saw I don't think many came in for repair, or very often.
It was a rather impressive demonstration of what kind of abuse the gun could take. It was winter, and the snow was a couple of feet deep. Using belts linked together, the gun fired a couple of thousand rounds in one looong burst! Then it was dismounted (coax gun) using asbestos gloves, and
thrown out of the loaders hatch, landing in the snow, and sinking out of sight in a cloud of steam.
The loader climbed out, dug up the gun, made sure the barrel was clear, remounted it in the tank, and fired another 2,000 rounds in one long burst!
No stoppage, no jam. We were impressed! The M219, which was an "improvement" of the M73A1, which was an "improvement" of the M73 was lucky to finish one belt without a malfunction! Actually that is a bit of an exaggeration, but with some of the tread heads running the thing it was true all too often. Here's an illustration,
I was part of the contact team at the Grafenwoehr ranges, and had my spade game interrupted. You could hear it coming, whenever there was machine gun firing, followed by a single shot, you knew there would be someone at the small arms truck within a few minutes.
So, here I am, just about to bust my sarg's nil when a tanker shows up holding the reciever of the coax gun (M219).
"What's wrong with it?"
"It don't f***ing work!". Apparently weapons diagnostics wasn't his strong suit. I took the gun, opened it, and started looking for trouble. Nothing broken, no obvious failures, not really any serious wear. In short I couldn't find anything wrong. So I gave it back to him.
"can't find anything wrong, try it again." He takes the gun and leaves. Back to the game.
About half an hour later, he is back, with the gun.
"Well?"
"It still don't ****ing work!"
This time, I dig out the manual, and detail strip the reciever. Everything that isn't welded or rivetted to the reciever comes off and gets inspected. There isn't any mechanical reason I can find for a malfunction. I reassemble it, and send him on his way.
About 45 minutes later, guess who? This time he not only has the gun, he has his CO with him, who is looking rather upset. I am also getting a bit pissed, because I
know the CO has been told that it is my fault his gun "don't f***ing work".
So, before he can come out with "Specialist, why haven't you fixed my F***ING GUN?!" (Captains in line companies are seldom polite to maint E-4s when they think they are in the right), I grab the gun from the loader and start walking towards the firing line. "Which one is your track?" I demand as they follow. This is a technical violation of the rules, which prohibit us from working on the guns on the firing line.
We get to the track, I hand the gun to the loader, and climb aboard. Loader follows, and inside the turret I tell him, "Okay, show me!"
He mounts the gun, puts a belt in it, pulls back the charging handle, and has the gunner trip the switch. The bolt moves forward slightly, and stops.
"I f**king told you, it don't f**king work!" the loader smugly informs me. The CO is in the t/c's hatch, watching.
I have spotted the problem. It is insufficient operator headspace.
There are two ways to load the gun. 1)with the bolt forward, you put the leading round in the belt behind the belt holding pawls, close the cover and pull the bolt back. 2) with the bolt back, you put the leading round of the belt against the cartridge stop on the feed tray, and close the cover. Anything else causes an instant jam.
The highly trained loader has placed the round against the stop on the feed tray with the bolt forward, closed the cover, and yanked the bolt back. Apparantly what he has done the previous times as well. So, naturally, it didn't f***ing work!
I says to the loader (so the CO could hear) "It's ******* broke, right?"
"******* A! it's broke!" he answers.
I open the cover, take out the belt, snap off about four rounds (to get the bent ones out of the way), load the gun correctly, and lean on the manual trigger. Gun chews it's way through the rest of the belt with no trouble.
"Yep, sure looks ******* broke to me!"
As I climb out of the track I can hear the CO starting to chew on the loader.
Later that day they had trouble with the .50cal on the Battalion Commander's track. A fresh faced 2nd Lt came to my shop truck, and
asked me if I would be willing to take a look at it. I'll save that story for another time.