Why is the M60 on its way out?

[Vern Humphrey]

What do you guys think is the ideal firing rate?

There are two ideal firing rates -- slow enough to be controlable and so fast the burst is gone before recoil forces you off target.

The first rate is around 400 rpm, the latter around 2,000. The lower rate doesn't eat so much ammo, or heat the gun so fast.

 

[entropy]

I was an Armorer, US Army, 86-88. I loved the 60's, but then, I had the wire-twisting pliers in my kit. I have seen the gas piston inserted backwards before. This turns your 60 into a 23lb. straight pull bolt action. My unit wasn't issued M249's, but I borrowed a few from a friend in the infantry, and took them out to the range for a little 'let's get to know each other', and on an FTX; surprised the Opfor, they knew we didn't have any belt-feds, and they were pissed when they found out I had one. They were also dead. (MILES dead, not the completely irreversable kind.) I never got to fire any M240's, but I did see and get to fondle one that belonged to some British redlegs that were training ours on the (then) new Light Gun.

 

[Preacherman]

If the MG3 (modern MG-42) could have a reduced firing rate, instead of 1200 RPM it would be a contender for best darn MG. What do you guys think is the ideal firing rate?

I'd rate the South African SS77 as the "best darn MG" out there (at least in 7.62x51mm. caliber). It has three rates of fire, controlled by changing the amount of gas allowed to vent from the system. At the highest rate (>1,000 rpm) no gas escapes at all; at the lowest, it's about 600-700 rpm. The highest setting is designed for use inside vehicles, so that occupants aren't gassed by exhaust fumes.

For more on the SS77, see here.

 

[Sam]

The 60's weren't really bad guns just not as good as it should have been.
Uses the 42 feed system with a lewis gun bolt. Sort of a comittee weapon. Too many compromises. Origonal configuration was with bipod and gas system fixed on the weapon instead of the barrel. Never have figured out why the change. Gas system on the barrel is livable, bipod is not. Then the silly glove!

Most are pretty old, the last new ones I got were E3's in 1987. They were too flimsy in the barrel for what we used them for. What I neede were 1917's what we got were M60's. The Vietnam era weapons I used were in pretty bad shape. Shot a lot and had not been to depot lately. Lots of chipped lugs. If you took good care of them they worked OK.
Sear engagement was not real positive, a direct acting thing and it is easy to not trigger teh weapon positively, that makes it easy to chip out the notch on the op rod or the tail off the sear and get a runaway.

The 240 is an upside down BAR with a belt feed and it is awesome, just shoots and shoots but we were looking for a coax gun when we bought it and just sort of expanded the contract.

 

[jeff-10]

Why is the M60 on its way out?

]

Your about 10 years too late asking that question. When I was in from 93-96 we were already replacing out M60s with M240s. The M240 is a far superior machine gun, its only downside is the weight.

 

[Tankcommander]

American tankers have been using the M240 since 1978, it replaced the M219 as the coax in M60A1 Rise tanks. We got rid of a total POS and got a truly great MG. I also used M60Ds on M48A5s. The 240 is the better weapon, stronger simpler and much more reliable.

Case in point 1 piece operating rod on the 240 slides right in, the M60 rod was 2 pieces and had to be lined up just right to go back together. Gun getting dirty but no time to clean 240 open up the gas regulator, M60 too bad.

TC

 

[Rebar]

I remember reading that 500-600 rpm was the idea rate for a machinegun. An updated mg42 limited to 600 rpm, that sounds like a nice weapon.

 

[MudPuppy]

Don't you have to cut a retaining wire to fully clean an M-60?

Anyhow, remember that MG-82 that CETME made (maybe still does)? Basically a scaled down MG-42 in 5.56, iirc.

 

[NMshooter]

The Ameli? I think that is how it is spelled.

Doesn't the M-240B have a rate reducer limiting maximum rate of fire to 600 rpm? Because too many folks were burning barrels and breaking parts otherwise?

Perhaps a rate selector switch like the M-1918A2 would be a useful feature.

Buddy of mine who got to shoot the MG-3 a bit when he was stationed in Germany said it was lots of fun to shoot, but very difficult to control. You basically sprayed rounds everywhere while wrestling with the gun.

 

[entropy]

The AMELI. I'd love to have one. Ironically, there were worries about terrorists getting a hold of them, and since they can be broken down into a couple small sub-assembies, hiding them here and there.

Yes, Mud Puppy. The gas piston retaining nut must be wired in, or it will back itself out muy pronto. I had to re-wire the majority of one unit's 60's after their dimwitted Armorer put the gas pistons in backwards. That and fixing the usual run-on/cook off and double feeds, earned me a Letter of Commendation from their CO.

 

[NMshooter]

So, Entropy, what do you think about that "M-60E4" that some company has been trying to sell for several years now? More of the same?

I thought the 60 was fun to shoot, but I never had to carry or clean one...

 

[jaysouth]

Bart,

The Germans claim that they can train gunners to handle 1200 rpm.

We say that's too fast and 600 rpm is adequate.

Having fired the MG-1, GPMG(general purpose MG, U.K. since 50's) and M-60, I have a non scientific preference for the GMPM which is what we call the M-240.

The MG-1 that I fired was Bundeswere issue and appeared to be the same as the WWII MG-42. I needed more experience to get the most of the cyclic rate.

However, I had a lot of experience with the M-60 in both defensive(tripod) and Offensive(bipod) modes. I also have a LOT of experice with an M-60 door mounted in a Huey. The M-60 never let me down nor can I recall an instance where a malfuctioning M-60 caused our troops any problems. I suppose there are other issues involving longivity and maintenance that were above my eschelon.

The current 240 is a fine gun although a little heavier. It appears that the Tripods, T&E mechanisms and other accessories give it more capabilities than the M-60.

One of the reasons that I got of the army was having to explain plunging versus grazing machine gun fire to too many junior infantry officers, who should have known how to employ a MG.

 

[entropy]

Looks like U. S. Ordnance tried to address most the problems the 60 had. I haven't held or fired one, however, so it's hard to tell if they were successful. Apparently the SEALS thought so, but I don't know if they still use them or not.

 

[SIGarmed]

I don't recall many problems with the E3 during the early and mid nineties if the guns were well maintained and the gun operators trained.

The E3 has the forward grip and lighter barrel. The gun would have a hot barrel sooner then the older 60 due to no pig barrel. Just don't loose the wiring near the grip or you'll loose parts when you go on a patrol for sure.

I liked it. I just didn't like to carry it through the brush forever.

 

[jdberger]

The only experience I've had is with the 240 in a tank. That thing was amazing. Always ran, clean or dirty, soaked in CLP or bone dry. The 240 was a champ. IIRC there were only 5 or 6 parts when you would field strip it.

When I was drawing "Z's" on crunchy targets, I always felt like Picasso...

 

[Crosshair]

I heard that with the M-60, if you assembled the bolt/firing pin wrong you could have a, "Fixed firing pin, straight blowback weapon."

Any truth to this?

 

[Jeff Timm]

The M-60 was a 'throw away" gun. It wasn't designed with a long life in mind. It wasn't "trooper proof" and in many ways could be assembled WRONG. It required maintenance on a regular basis, including filing off the burrs. It's rivited receiver was loose and had to be "improved" by welding. Unfortunately welding it was a pain in the tail.

Step 1. check alignment with gauge.
Step 2. have welder apply two welds, one on each side of the receiver.
Step 3. check alignment with gauge.
Step 4. Reassemble gun, send to depot for destruction and recycling because until the welder had done four or five, he didn't get the 'hang' of the receiver on the welding table.

Efforts to provide a real welding jig were locally fabricated and of limited usefulness.

Geoff
Who was a 45B20 way back when. US Army Ordnance Corps 1972 -82.

 

[Vern Humphrey]

Perhaps a rate selector switch like the M-1918A2 would be a useful feature

One reason why I think we should take a hard look at the M1941 Johnson Light Machinegun. It weighed only 12 1/2 pounds, won praise from those who used it in combat, and had two rates of fire -- 450 rpm from an open bolt, and semi-auto from a closed bolt.

Shorten the receiver for 7.62X51mm, trash the magazine feed arrangement, add a belt feed, use modern materials, and you'd be close to 11 lbs for a battle-proven machine gun.

 

[Sergeant Sabre]

One of the reasons that I got of the army was having to explain plunging versus grazing machine gun fire to too many junior infantry officers, who should have known how to employ a MG.

I am well aware of the difference between plunging and grazing fire. However, I was never a machine-gunner, so I would be grateful if somebody could briefly explain to me the pros and cons of each.

I imagine plunging fire would make it much more difficult to find effective cover, but grazing fire would make your fire effective over a longer range.

Could somebody quickly elaborate?

 

[Hobie]

I remember one of my early PSGs, "make that pig ROOT boy!" He LOVED hearing his two guns sing to one another, "6 to 9 and keepin' time" he would say, again with a BIG grin. He KNEW how to make the gun work and keep working and yes it will when well maintained. However, these guns were just used up by those that couldn't or wouldn't. The 240B is a better gun.

BTW, weight of about 25 lbs is unimportant as long as the gun WORKS. Remember, the gun weighs less than the rest of the combat and survival loads.

 

[Vern Humphrey]

I am well aware of the difference between plunging and grazing fire. However, I was never a machine-gunner, so I would be grateful if somebody could briefly explain to me the pros and cons of each.

I imagine plunging fire would make it much more difficult to find effective cover, but grazing fire would make your fire effective over a longer range.

Could somebody quickly elaborate?

Grazing fire is fire that doesn't rise higher than a man -- it skims the ground so anyone walking between the gun and a point some 750 meters away will be hit. You manipulate the traversing and elevating (T&E) mechanism to get the full 750 meters, moving the muzzle up and down slightly while firing.

In a properly-laid out defense, grazing fires are integrated with the obstacles -- imagine barbed wire entanglements laid out in a pattern of XXX. Machine guns are sited at the friendly ends of some of the Xs, to deliver grazing fire down the enemy side of the obstacle, so troops bunching up against the wire are easy meat.

Of course, you must also identify dead space (dips where grazing fire won't reach) and cover that with some other weapons -- grenade launchers, mortars or artillery.

Plunging fire is the counter-definition of grazing fire -- it rises above the height of a man. Plunging fire may be dictated by the shape of the ground (firing from one hillside into another, for example) or by range. In general, the angle of fall of small arms projectiles is not great enough to make overhead cover a necessity (it's artillery and mortars that does that.)

A primary advantage to plunging fire is that it can be delivered over the heads of advancing troops. There is a method for doing this safely, called the Gunner's Rule. The gun is laid on target, then the sights are raised to determine the limit of friendly advance before you have to cease or shift fires.

 

[BruceB]

The Johnson LMG, updated, 12.5 pounds and belt fed......

This is the very definition of a "TEMPORARY" machinegun. .30-caliber full automatics for the machinegun role NEED WEIGHT. Why do you think the Browning Automatic Rifle is a "rifle" and not a "machinegun"? It's because, even at a weight of eighteen pounds, let alone 12.5 pounds, it does NOT have the ability to deliver sustained auto fire. It overheats very quickly, and has no barrel-change capability (unless its an FN (D), which is extremely rare).

The weight, particularly barrel weight, performs a heat-sink function that reduces the rate at which the gun heats up. Less weight = hotter/sooner, and HEAT is the enemy of auto weapons. The weight also means heavier and more robust working parts, also leading to more-reliable function under full-auto fire, which imposes extreme stress on everything in the gun.

I was trained on the Bren LMG in the Canadian Army, and was there when the 5-pounds-lighter FN C2 heavy-barrel FAL replaced the Bren (Mark 3 Brens are under 20 pounds...earlier Marks are heavier). There is no comparison, either for accuracy OR sustained-fire ability...the Bren is a machinegun, and the C2 is a rifle. It would have been far better and less expensive to simply convert the Bren to 7.62 NATO (as the Brits did) to serve beside the new FAL rifles in the infantry.

There is a price to pay and a trade-off to be made for every physical factor in a machinegun. Lighter weight seems desireable UNTIL one needs the gun to fire accurately and function for a relatively long period. It then becomes apparent that a few extra pounds can be a very good thing indeed.

 

[Vern Humphrey]

This is the very definition of a "TEMPORARY" machinegun. .30-caliber full automatics for the machinegun role NEED WEIGHT. Why do you think the Browning Automatic Rifle is a "rifle" and not a "machinegun"? It's because, even at a weight of eighteen pounds, let alone 12.5 pounds, it does NOT have the ability to deliver sustained auto fire. It overheats very quickly, and has no barrel-change capability (unless its an FN (D), which is extremely rare).

The Johnson, unlike the BAR, has a quick-change barrel. Given it's light weight, you can afford to have a few extra barrels in the trains. In addition, its low rate of fire (about 450 rpm) also aids in slowing overheating.

Note also that with its semi-auto capability, in many roles the semi-auto function would be better than burst fire.

One of the prices we pay with weight tradeoffs is we simply leave the heavy gear behind (remind me to tell you sometime about a chemical attack on the 10th Mountain Division at the Joint Readiness Training Center. Guess what they had decided was too heavy to carry?) A light weight full-power machinegun that you have in a firefight is better than a similar, but heavier one back in the rear.

 

[Hellion Productions]

Having toted and fired both the M-60E3 and M-240G during my stint in Uncle Sam's Amphibious Death Cult, I would take the heavier and more dependable M-240G any day of the week over the rattle-trap, yet lighter, M-60E3. The M-240G definitely hates blanks, though. The important part, though, is that it loves linked 1 to 4, tracer and ball .

Best,
John Bear Ross

 

[Teufelhunden]

The M-240G definitely hates blanks, though

A cigarette filter stuck behind the BFA works wonders in getting them to operate with blanks. The butt blocks the small hole in the BFA and forces all of the gas to return to cycle the bolt. Tough on the guns in the long run through...

-Teuf

Radio Op/Armorer/Combat Engineer/ Amphibious Assault Warrior Extraordinaire.