View Full Version : The M3A1 'Grease gun' was a rude, crude, and effective submachine gun

March 19, 2011, 08:51 AM
I wrote a couple articles on the M3A1 'Grease gun' for my Michigan Firearms Examiner column.

The M3A1 'Grease gun' was a rude, crude, and effective submachine gun (http://www.examiner.com/firearms-in-detroit/the-m3a1-grease-gun-was-a-rude-crude-and-effective-submachine-gun)

"The M3A1 “Grease gun” was one of the simplest, ugliest, and cheapest personal weapons ever fielded by the U.S. military. But, as one U.S. Marine combat veteran recently recalled, what this crude submachine gun lacked in looks, it more than made up for with brutal effectiveness."

This article includes a brief interview with a Korean War vet. I wish I would have got more of him on tape as he was a hoot!

Here's the second article. This one has footage from a U.S. Army training film with added footage of me shooting a Grease gun at the end. Watch how the brass hits the camera.

Shooting the M3A1 'Grease gun' (http://www.examiner.com/firearms-in-detroit/shooting-the-m3a1-grease-gun)

March 20, 2011, 12:57 AM
Nice, thanks for sharing. I always like reading stories about utility weapons such as the M3A1 "Grease Gun" and the FP-45 "Liberator".
Not pretty, but functional and served their soldiers well.

March 23, 2011, 12:40 AM
The M3 was the second subgun I fired. The first was a Thompson.
I shot the M3 better because of the slow rate of fire.
Shot a suppressed one at the old Second Chance Bowling Pin Shoot. The clank of the bullets hitting steel targets was louder than the sound the gun made firing.

I've always liked the Grease Gun.
Neat interview with the Korean War Vet too.

March 23, 2011, 08:01 AM
There are two models of the greasegun. The M3 has a crank handle to retract the bolt. The M3A1 has a finger hole in the bolt.

March 23, 2011, 08:17 AM
Exactly correct, and by closing the dust cover with the bolt retracted, a projection entered the depression for the finger, thereby giving a safety feature to keep the bolt from moving forward unless the dustcover was open. I really like the M3.

March 23, 2011, 09:05 AM
So it was rude, huh? Are there well mannered guns?

I remember seeing arms rooms full of submachine guns (armor units) when I was in the army, when doing CMMI inspections or something like that (only been 42 years). They never struck me as crude.

March 23, 2011, 09:23 AM
I see the M-3 as elegance of design.I like the bolt running on guide rods,one feature of the AR18/180 I like.

kframe:Your quote,L Neil Smith used to reside in my city,Ft Collins,Co.I met him,long ago.His book"Probability Broach" was an interesting read:Parallel dimension,very much a gun culture,and quite Libertarian

March 23, 2011, 10:51 AM
The M3 - M3A1 was a very effective design, low cost, easily manufactured. I was issued one in 1976 and qualified with it. I later destroyed it by running over it with a tank and had to reimburse the government for the cost of the weapon. I wrote a check to the Gummint for about $8.00 after depreciation.

Were it legal, I'd buy a whole crate of them at $8.00 each.

44 AMP
March 23, 2011, 04:30 PM
And they are "crude" in the sense that a firearm made mostly from stampings was considered "crude" in the era of WWII.

Personally, I rate the M3/M3A1 as less "crude" than the STEN gun, and actually a rather elegant economy of design.

They do have their weaknesses, but for the time, the design is nothing short of genius in many ways. IIRC original cost to Uncle Sam was $17.50 per unit. Compare that to over $100 for a Tommygun.

The Grease gun is simple, robust, and rugged. It has a low rate of fire that makes it very controlable, small size, and it handles and points as well as anything contemporary in its class, and better than some.

The only parts that are problems are; stocks get bent, and the finger tab on the barrel nut retaining sping breaks off. Thats about it. Did see one once where the safety tab on the cover had broken off. But only one.

The "grasshopper leg" cockking lever system of the M3 can give trouble, and if yiou get it jammed, brother you got a JAM. Thats why it was done away with on the M3A1.

Still in service in tanker units in the 1970s (and likely later) mostly M3A1s, with the occassional M3, they were a lot handier inside a vehicle (and getting through hatches) than the M16!

Considering all factors, including service life, I'd have to say the M3 series SMG was the most cost effective firearm the US ever had.

March 23, 2011, 08:05 PM
I wish I could have one, after renting one at a range in Central Texas last summer. Man, was that thing fun with a capital "UN"...err, "F"

March 24, 2011, 09:58 PM
I later destroyed it by running over it with a tank

This is my quote of the week! love it!

44 AMP
March 24, 2011, 10:43 PM
Update: I spoke with a fellow today who told me that his tanker unit still had greaseguns as issue weapons in 1984, when he got out.

Anybody out there got a later in service date?

Not a bad record, considering.

March 24, 2011, 10:49 PM
Was an "unauthorized weapon", but I carried one in Vietnam with another 30 rd mag taped in oppsite direction to the one inserted. Those were the days:D

Semper Fi

March 24, 2011, 11:26 PM
they were still in use in the 91 gulf war, our A & B Plt. used them. they just loved them, when i got of the army in 93 they where still using them.:D

April 12, 2011, 02:43 PM
Update: I spoke with a fellow today who told me that his tanker unit still had greaseguns as issue weapons in 1984, when he got out.

Anybody out there got a later in service date?

A buddy of mine said his Michigan National Guard Armor unit had them until the mid '90s. He said they regularly qualified with them up until the last couple years that they had them. They'd finally turned in their 1911's a couple of years before they got rid of the Grease Guns and after they turned in the 1911's they no longer received any new .45 ACP ammo. Once the ammo supply got tight they stopped qualifying with the Grease Guns.

He really liked the M3A1 and thought it was a better tanker weapon then the M4. (He said their M4's were rebuilt from uneeded Bradley firing port weapons, but I have no idea if that's true)

April 12, 2011, 05:18 PM
I wouldn't say it was "rude or crude", compared to the Thompson it is very inelegant but the M-3/M-3A1 were designed to be massed produced using stampings and similar methods to keep costs down, speed up production and allow the used of inexperienced labor with minimal training.
I fired one only once, when I was in a Mech Infantry battalion in the NJNG 30 or so years ago. Only fault I saw in it was that it was fully auto only.

April 12, 2011, 05:51 PM
We had a point man that came up with one somewhere, it was a heck of a lot of fun to shoot, he finely got rid of it and went back to his CAR because the ammo was so dern heavy.

Later I was the Weapons Sgt in a NG Special Forces company, (No I wasn't flash qualifed). I had several Forgien weapons and some older US weapons (1919A6, BAR, and Grease gun). We got a lot of ammo for it but we couldnt get it to jam. We had an Armor BN that had them up until 73 when they lost their armor status. They had to turn over their armor to the Regular army to replace what they shipped to Israel during the '73 war. The SF Unit (38th Special Forces) was disbanned in 76 and I had to turn in all my neat guns.

April 12, 2011, 06:18 PM
I was a Tanker from the mid 70's to the end of 91. The M3A1 was the crew served weapon on the M60A1, M60A2, M60A3, That weapon was fun to shoot:D, you could see the bullets as they went down range from the gun. We had a curved barrel that was for shooting around corners, maybe about 15 to 20 deg.curve at the most. Than transitioned to M1A1 tanks in about , ya 1984 was when I transitioned to the M1A1.

Romeo 33 Delta
April 12, 2011, 08:23 PM
I had an M3A1 and a bag of mags on my M-113A1 ACAV in Viet Nam in 1968. Kept it hanging right outside the front of my driver's compartment ... nice and handy. Never had to actually use it in a combat situation ... but it was fun to blast with, but as I rememeber, loading the mags was very tedious.:D

April 13, 2011, 05:23 PM
As long as you're using ammo that's loaded hot enough, that is; I once fired an M3A1 (with "American Eagle", Fed's off-brand, IIRC) that didn't quite have enough oomph to get the bolt to get all the way back to catch on the sear, and had a "run-away" that lasted for several seconds.

May 19, 2011, 02:47 AM
Rude & crude were how I heard most US Army veterans describe the M3A1 .45acp SMGs.
My US Army recruiter, a tanker, told me they POSs that never worked properly in his units. He served in Europe(Germany) in the 1970s & early 1980s.
Author & SF/spec ops veteran John Plaster wrote in his non fiction SOG books that the troops in SE Asia who served in the MAC-V-SOG never liked the "grease guns" or the 9x19mm Swedish K SMGs.
Plaster wrote these sub guns were nearly worthless & most SOG teams wanted AK-47s, CAR-15s or the standard M-16a1 5.56mm.
The US Army & CIA/DIA/etc let them buy & use almost any firearm they wanted for these covert & special missions.


May 27, 2011, 09:15 AM
"by closing the dust cover with the bolt retracted, a projection entered the depression for the finger, thereby giving a safety feature to keep the bolt from moving forward unless the dustcover was open"

NOPE! On both counts.

The tab on the inside of the cover entered to finger hole in the bolt only if the bolt was forward. It was intended to prevent the bolt from moving to the rear (not forward) with the cover closed. This was considered necessary in case someone had the M3A1 slung over their shoulder, barrel up, with a loaded magazine inserted, then jumpped from the bed of a truck to the ground (apparently exactly that did happen with an M3 at least once) although there are other ways to bang the gun in such a way that the bolt could move to the rear. If the bolt moves far enough to the rear to catch on the trigger mechanism, no problem, it stays back. If the bolt moves to the rear only an inch or so, no problem. If the bolt moves far enough back to pick up a round from the magazine but not far enough back to engage the trigger then you get one very loud OOOPS!

As for the tab on the cover stopping the bolt from coming forward, it wouldn't stop the bolt unless someone or something was holding the cover closed. The rear edge of the tab on the cover was slanted so that the bolt would push the cover open on its way forward.

May 27, 2011, 03:02 PM
Tankers I knew hated em. They could barley qualify with em and felt it would probably have more of an effect if the enemy were hit in the head by a thrown one.

That's what a tanker told me "I can't hit nothin with it, they're so dang heavy it'd probably work better if I just threw it - I'd knock the enemy out if I hit em in the head."

I think they were phasing them out right at that time. Didn't tankers get issued new weapons along with the M1 Abrams? We were switching from the M60s right about that time. I think we had M60A3s, before I left I was seeing the Abrams.

Still y'know - I have a TEC-9M and it's fun to shoot. I'd take a grease gun even a semi-auto version.

May 27, 2011, 03:08 PM
Wait a minute:

The M3A1 was the crew served weapon on the M60A1...

I just re-read this...

The M3 is not, and never was a crew served weapon.

May 27, 2011, 06:03 PM
having owned both a STEN MK II and a M3A1 greasegun....I would take a STEN anyday over a M3. I would have felt shortsheeted being issued a M3 as a infantryman's weapon.....its indeed worth the $13.00 dollars they payed for each one, but not a penny more lol.

May 27, 2011, 07:23 PM
My National Guard unit still had some M3 greaseguns in the mid to late 1990s, don't remember what year they finally got turned in. They were assigned to our recovery vehicle operators, part of the system of the recovery vehicle.

I got to handle them, but never fire them. The soldiers assigned those weapons did get to fire them once, but sadly I didn't get a chance to shoot them that time.

May 27, 2011, 07:44 PM
You are right, it was a crew issued weapon. 1/64AR, 2/64AR, 2/6CAV,3/7CAV,
3rd ACR, 11th ACR.

Not crew served:o

May 28, 2011, 12:12 AM

June 9, 2011, 08:24 AM
Clearly, opinions vary of this weapon, probably just about as much as opinions vary on every other weapon.

Mike Irwin
June 9, 2011, 09:08 AM
I know one person who had considerable experience with a grease gun, and he was quite fond of it. He primarily liked how compact it was and the fact that when called on to clear houses in Europe, he said it was a LOT easier to maneuver in cramped stairwells and hallways that are found in many older European homes.

James K
June 9, 2011, 11:02 PM
Hi, n4aof,

Partially wrong on the M3, totally wrong on the M3A1. The dust cover of both the M3 and the M3A1 served as the safety. If closed with the gun cocked, it blocked the bolt from going forward and moved the bolt back off the sear. The M3A1 was improved by having the tab on the cover enter the cocking hole in the bolt when the bolt was closed, thus it prevented the bolt from moving due to inertia so it was safe in that regard as well.

The safety was positive; releasing the bolt with the cover closed could not and did not move the cover out of the way. If that happened, the gun was defective.

Incidentally, the M3/M3A1 played another role in gun lore. It served as the inspiration for Bill Ruger to make the frame of his original .22 auto pistol the way the Grease Gun was made, from two stamped pieces of steel welded together. And that was the start of a firearms empire.


July 22, 2011, 04:35 AM
This is the end stage development of the M3A1 . It started life as a SpitFire made in Phx Az in the 1960's . The SpiteFire ran at about 800 rounds per minute. It was a real ammo waster . After replacing the internals with those of the M3A1 it runs at the more reasonable speed of about 300/350 rpm. At that rate it is able to produce single shots with only trigger control . I also replaced the M3A1's trunnion with the UZI type that made it much easier to replace barrels .
As produced
As modified
Field Stripped
Detail Stripped

July 24, 2011, 09:16 PM
I have fired the M3 full auto and I liked it more than the Tommy Gun.

July 25, 2011, 02:02 PM
8.5 lbs?!!

I had no idea those things were that heavy! That's only about a pound lighter than an M14. Wow.


44 AMP
July 27, 2011, 01:51 PM
8.5 lbs?!!

I had no idea those things were that heavy! That's only about a pound lighter than an M14. Wow.

It may seem heavy, but its stll lots lighter than a Tommygun! By a couple of pounds!:eek:

July 27, 2011, 04:30 PM
It may seem heavy, but its stll lots lighter than a Tommygun! By a couple of pounds!

Yeah, I suppose so, but the Thompson looks heavy. I just never thought the grease gun looked that heavy I guess. Just looks like thin stamped steel, I'd have figured maybe 5 lbs empty. Learn something new everyday. :o


July 27, 2011, 04:30 PM
The suppressor was big & heavy enough to beat someone to death with it.
I once had the end cap come off the can while firing and the gun sprayed washers to the target line.

It was a simple and effective weapon whose compact size also made it easy to rig for parachute operations.

July 27, 2011, 06:21 PM
id take this weapon over any other SMGs over any day of the week especialy the thompson.

July 27, 2011, 09:33 PM
id take this weapon over any other SMGs over any day of the week especialy the thompson.

Why is that?


November 3, 2011, 02:36 PM
We pulled out my friends M3A1 Grease Gun and Thompson a few months back and dusted them off.
Me on the Grease Gun. About a 10 lb trigger for the open bolt. Watch me tug after the mag was empty.


My son hosing the Thompson. First time for him on the Thompson.


And my son with a little better control.


November 21, 2011, 02:40 AM
In the video referencd by the OP regards a Korean War Vet describing his experience with the M3..........the vet makes the statement that his "24 inch E2" or words to that effect.

To what weapon is he referring. He state it failed, he disabled it by bashing it over a rock, and picked up an M3.........