Stuff I worked on in the army.

[Big Frank]

In Germany, we had a guy in our company I only saw a few times. he was on a contact team attached to an infantry company in Crailsheim, while the rest of us were based in Illesheim 60km NE of him. I think it was another company of 1/6 Infantry, which I also supported, and was called First in the Sheep, instead of 1st in 6th, after the news we heard one day out in the field. One guy in the 1/6 Infantry had a sheep that was his girlfriend, and he didn't want her fooling around with anyone else, so he locked her up in his wall locker. Eventually someone wondered what the horrible stench was coming from his room, and when they cut the lock off his locker they found out.   Our battalion HQ was 30 clicks SE of us in Ansbach, and 50k ESE of Crailsheim. The 3 places formed a big triangle, and other companies in my battalion were spread out in a few other places, too. Stateside they crammed everyone together as close as possible, and in Germany we were spread out like peanut butter on a cracker.

Before I left Germany, "Little Davy D." at Crailsheim had a bunch of M60s that had chips on the bolt lugs and locking recesses. Apparently the unit armorer(s) never noticed and didn't bring them n for repair. When he found out how bad they were, and how many of them were bad, we had to check every one of them in our company and all the companies we supported. There were also problems with the operating rods on some of them, like the roller cracking and falling off, which also gouged out a groove on the op rod.

So I ended up replacing a lot of M60 Barrel Assemblies, Bolt Assemblies, and Op Rod Assemblies. IIRC the NSN (National Stock Number) for the 3 parts were as follows:

1005-00-608-5001 - Barrel Assy.
1005-00-608-5002 - Bolt Assy.
1005-00-608-5003 - Op Rod Assy.

They were 3 consecutively numbered parts, which I don't recall seeing anywhere else, but I usually didn't have to order 3 related parts at a time, and only 3 parts. The 1005 in the NSN identifies the Federal Supply Classification Group, denoting weapons (from 1 mm through 30 mm. The 00 or a 01 is the National Codification Bureau code for he United States of America. The last 7 digits are the Item Number, and 608 just happened to be 3 digits for the M60 parts I ordered so many of, which made that easy to remember. And the rest was as simple as 1, 2, 3, almost. If anyone wants to look up an M60 TM 23&P to check the accuracy of the numbers I listed, they're online. I personally haven't looked them up in 40 years, and I could be wrong. Also, a lot of numbers could have been changed due to updated parts, and everything switching to NATO Stock Numbers.

https://en.wikipedia.org/wiki/NATO_Stock_Number

https://en.wikipedia.org/wiki/Crailsheim

https://en.wikipedia.org/wiki/Illesheim

https://en.wikipedia.org/wiki/Ansbach

We had a lot of M60s that were falling apart because the rivets in the middle (yellow arrow) were loose. They were all turned in to Depot for rebuild, and supposed to have new, improved rivets so they didn't fall apart again. These guns had a lot of use from the 1950s - 1980s, and some had loose rivets on the small piece at the back of the receiver (red arrow) too. Despite all the problems, I still like the M60. I just wouldn't want to carry one.

[Big Frank]

And of course, I worked on the M16A1 rifle, but no other variants of it.

https://en.wikipedia.org/wiki/M16_rifle

[Big Frank]

I worked on the Smith & Wesson Model 10 six-shot, .38 Special, double-action revolver with fixed sights. The Smith & Wesson Model 10 was previously known as the Smith & Wesson Military & Police revolver. During my training at Aberdeen one of the instructors passed one around that had its side-plate removed so everyone could see how it worked when you squeezed the trigger, or cocked it and dropped the hammer. That was the extent of my training on it. IIRC that was a marine Gunnery sergeant (E-7, equal to an army Sergeant first class) we all called Gunny. I can't recall his name, but he also brought in an M24 sniper rifle for us to see one day. The army was still using M21s at that time. The marine corp was too small to have its own school so they trained with us at APG in Maryland, at the The US Army Ordnance and Chemical Center and School, USAOCC&S.

Helicopter crews were issued .38s and I only remember having one come in for repair when I was in Germany. The front sight was bent (or broken), so the barrel needed to be replaced. The whole time I was in the army, that was the only weapon out of thousands I worked on that I remember not being able to fix that didn't go to depot, Level 5 maintenance for complete rebuild or replacement. I was Level 3, direct support, and after I inspected it, that one had to go to Level 4, general support. That was a different company in my battalion that had the proper tools. Level 1 maintenance is crew/operator, and Level 2 is unit maintenance by armorers, who were usually supply clerks with some training on weapons. I can't remember if the .38 that came in was a 2" snub-nose, or a regular 4" barrel version. The army had both of them. I think pilots had snubbies in a flight-suit pocket, and crew chiefs carried the 4" in a holster, which was probably what came in that day. Other aircrew members may have been issued M1911As, but I don't know. I just know that some of the guys carried .38s. I supported Infantry, Armor, and Artillery at Fort Polk, half Infantry, and no Aviation. I never saw a revolver in use there. I supported Armor, Infantry, and Aviation in Germany, mostly Armor, and no Artillery.

https://en.wikipedia.org/wiki/Aberdeen_Proving_Ground

https://en.wikipedia.org/wiki/Smith_%26_Wesson_Model_10

https://en.wikipedia.org/wiki/M24_Sniper_Weapon_System

https://en.wikipedia.org/wiki/M21_Sniper_Weapon_System

[Big Frank]

A couple more things I worked on were the M29 81mm (3.2 inch) mortar and M30 4.2 inch (107mm) AKA the Four-deuce. The M29 was replaced by another 81mm in 1987, and the four-deuce was replaced by a 120mm mortar in 1991. The M29 weighed 52 pounds, was easily portable, and usually serviced by a crew of five. I think 2 of them were only carrying ammo. The M30 is a whole different story. It weighed 672 pounds!!! Due to this heavy weight, the mortar was most often mounted in a tracked mortar carrier of the M113 family, designated as the M106 mortar carrier. This vehicle mounted mortar was crewed by five people: the track commander (mortar sergeant/gun commander), gunner, assistant gunner, ammunition bearer and vehicle driver. Ground mounting of the mortar was time consuming and strenuous as a hole had to be dug for the base plate of the mortar to rest in, sandbags had to filled and placed around the base plate to stabilize it and to protect the exposed ammunition. Also, this decreased the accuracy of the weapon as the recoil from firing caused the base plate to shift in the ground. This movement also made the crew have to "lay" the gun back on the aiming stakes more often, causing a temporary lack of fire while the weapon was re-positioned and re-sighted back to its original reference point. I can't remember if the man-carried M30 had a crew of 9 or 13 or what, but it took a lot of people to carry different parts of it. At least 1 man to carry the standard, and maybe the sight in a box, 1 to carry the rotor, 2 to carry the baseplate, 2 to carry the bridge, and 2 to carry the cannon tube. And anyone who wasn't carrying parts of the mortar carried as much ammo as they could. The shells weighed 25 pounds apiece give or take a few pounds, depending on what kind they were. There was an M125 mortar carrier similar to M106, but with the 81 mm M29 mortar.

The M29 shells have fins like rockets and the charges are like packets of gunpowder clipped onto the rear. You clip on however many it takes to do the job. M30 shells are like bullets with square sheets of propellant stuck on the stem at the rear. You add or remove squares to adjust the range by 50 yards per square. The cannon (also referred to as the barrel) is a rifled tube 60 inches long with an inside diameter of 106.7 mm (4.2 inches) between lands. This rifling consists of 24 lands and 24 grooves of which the first 9 inches), as measured from the base inside the barrel, are straight. The twist increases to the right from zero at this point to one turn in 84 inches. It's the only thing I worked on, and maybe even saw, with gain twist rifling. The rounds have an expandable ring at the base, which expands into the rifling under the pressure of the firing charge. The M29 had its rifling on the outside of the tube.   The whole outside of it was threaded, except the last few inches at the bottom. It was a smoothbore since they were fin-stabilized projectiles.

https://en.wikipedia.org/wiki/M29_mortar

https://en.wikipedia.org/wiki/M30_mortar#

https://en.wikipedia.org/wiki/M106_mortar_carrier#

Here's a video of the ROK army shooting 60mm, 81mm, and 4.2" mortars. I didn't have anything to do with 60mm mortars but have seen different ways they were deployed. Including using your helmet as a baseplate, holding the mortar one-handed and firing it all by yourself. No bipod or anything, just Kentucky windage, and elevation. 



https://www.youtube.com/watch?v=z4oTWiORasM

[Big Frank]

The mortar carriers didn't use all the same parts as the ground-mountings, which means there was more to work on. But it was usually M29 T&E mechs, and the same thing on M30 standards, but alsoother parts of the standard, and repacking the shocks, among other things. Plus the usual borescope and pullover gauge on both. Whether you were gauging a mortar, tank, or howitzer, you had to do the same thing with a clean cannon. Assemble the head of the gauge to the handles that are marked like rulers so you can check at certain depths, slide the moveable part out of the head until it was wider than the bore diameter, literally pull one handle over, hence the name, pull the gauge out and measure it with a verier caliper. There are also stops that clamp onto the handle to make sure you're at the right depth. We never had digital calipers or dial calipers, and if you never used a vernier caliper before it takes a little getting used to. Especially if you never used any kind of calipers before.

[Sponsor]

[Big Frank]

M106 mortar carrier with four-deuce in action.



https://www.youtube.com/watch?v=8KOvMK1JJu8


https://www.youtube.com/watch?v=Qutid8jBBp0


https://www.youtube.com/watch?v=x0En-nqXal4

[Big Frank]

When I was outside working on my ATV I heard someone's mower suddenly stop like it hit an immovable object. I thought to myself, I recognize that sound. I'm familiar with stoppages. As as soon stoppages entered my mind, I thought about the M73/M219 machine guns and realized I never did finish this thread. It's weird how my mind works sometimes, but at least I finally remembered and will try to get around to posting more this weekend.

[Big Frank]

I keep thinking I need to check this thread because I don't remember finishing it. Then when I have time to check it I've already forgotten about it. I just remembered something about the M203 grenade launcher that anyone who has one needs to be aware of. Back in my time in the army, some of the M203s had excessive firing pin protrusion. I don't know how bad it was, but I think that it could cause pierced primers. I don't think the firing pin was resting on the primer, but I don't remember how long the firing pins were relative to the length of the receiver. If you've ever pierced a primer on a gun, you know you don't want to do the same with something capable of throwing grenades 400 meters, about 1/4 mile. With the high–low pressure system built into the shells, the primer is in the high pressure chamber. There was no gauge for us to measure firing pin protrusion on them, so the replacement firing pins were made with 2 horizontal grooves to identify them. If you take the cover plate off the back of the launcher, you can see the grooves without taking anything else apart. If it looks like the illustration I made it's good to go and you pop the cover back on. If the firing pin is round, and doesn't have the grooves on the sides, don't shoot it until you get the firing pin replaced. It might blow up, or go off when you bum it, whatever the problem was. The empty shells were much better feet for our beds than the actual feet were, which sometimes fell off when you moved your bunk around to clean the floor, etc.

https://en.wikipedia.org/wiki/M203_grenade_launcher#

https://en.wikipedia.org/wiki/MEI_Hellhound_(grenade)

https://en.wikipedia.org/wiki/United_States_40_mm_grenades

[Big Frank]

Some of the Ma Deuces we had in the '80s had the old style rear sights with a built n scope mount. I think Carlos "White Feather" Hathcock sniped someone at an extra-long distance with one of these in Vietnam. The newer model rear sight bases look like HEAVY sheet metal folded at 90 degrees on both sides, instead of being milled from a billet of steel.

[Big Frank]

This is what the sear in an M60 machine gun looks like in the correct orientation. And when it's rotated 180 degrees so it's upside down and backward. And those grunts over in Germany were surprised when it started firing as some as they let the bolt fly forward. That just goes to show you that they can make things foolproof, but that can't make them grunt-proof. That's why they had no business messing with it. I wouldn't have believed the sear fit in that way if I didn't see it for myself. I don't know if that's even possible with any other gun. It didn't take me long to diagnose that one. "Well, that's your problem right there."