The M3 “Grease Gun” was designed to save money and kill Nazis

If this weapon was your sibling, it would be the rude, crude, and socially unacceptable little brother who helped you curb-stomp the neighborhood bullies. Nobody really loved the M3 submachine gun dubbed "the Grease Gun" by GIs. But nobody really hated it, either.

It was so cheaply made it looked like a mechanic's tool rather than the product of advanced American industrial know-how.

"By the Korean War, the M3 and M3A1 were used in greater numbers than the Thompson," said Alan Archambault, former supervisory curator for the U.S. Army Center of Military History and former director of the Fort Lewis Military Museum at Joint Base Lewis-McChord near Tacoma, Wash.

It was supposed to serve as a replacement to the iconic and expensive Thompson submachine gun, but developed a reputation of its own that kept it in the U.S. military inventory from World War II all the way through Desert Storm.

"Although unattractive and cheaply made, it was a practical weapon," said Archambault, a U.S. Army veteran who is also an artist and illustrator who specializes in military subjects. "The weapon did have close-range stopping power: A visitor to the Fort Lewis Museum once told me the story of shooting a Chinese soldier at close range and knocking him out of his boots like in a cartoon or a Three Stooges movie."

During World War II, there was almost a desperate urgency to manufacture vast quantities of weapons as quickly and cheaply as possible – particularly submachine guns.

In the 21st century, we are used to weapons made from exotic materials and possessing high-technology features that maximize killing power. Back then, the materials used for these hastily produced SMGs looked like they were purchased on sale at the corner hardware store.

The British did it by producing the Sten Gun, a 9 x 19-mm submachine gun made of steel tubing and sheet metal that bears a similarity to a piece of plumbing. In fact, one of its nicknames was "the plumber's nightmare."

So did the Russians when they made the PPSh (pronounced "puh-puh-shaw" because of the sound of the Cyrillic letters in the weapon's name), a 7.62 x 25-mm submachine gun that was often produced in auto shops by unskilled labor.

The United States was no different when it came to producing a quick-and-dirty alternative to the Thompson. The M3 is an ugly hunk of metal – words like "crafted" or "elegant" simply are not applied when discussing the looks or pedigree of the weapon.

Made of stamped metal parts like a General Motors car – not surprising when you remember it was produced by the same division that made metal automobile headlights – the M3 is not a submachine gun noted for its fine tolerances and sleek design.

It has no adjustable sights, no selector switch, no fine-grained wood furniture, and few milled-steel components. It was welded together, and the user could see the welds on the weapon's exterior.

Even the butt stock is simply a bent, U-shaped length of heavy wire.

"The advantage was that the M3 was easy to manufacture and much cheaper to make than the Thompson submachine gun," said Archambault, who said only the barrel, breech block and parts of the trigger mechanism were made of machined steel.  Yet, that simplicity allowed the manufacture and distribution of more than 600,000 M3s during World War II alone.

Besides, it saved the government money.  The iconic Thompson submachine gun – a sleek, well-made weapon highly prized by any GI who could get his hands on one – cost Uncle Sam about $225 each.

That is about $3,000 a weapon today when you adjust for inflation. A new Grease Gun cost the government about $20 each, or about $260 a weapon in today's dollars.

It is a beast to carry. It weighs nearly 11 pounds when it has a full 30-round magazine inserted, and the extra magazines weighed several pounds each when loaded.

But it spewed .45-caliber ACP bullets at 450 rounds per minute, was simple to operate, compact because the butt-stock collapsed, and it was disposable.

Yes, disposable: Until 1944, soldiers and Marines who had M3s that had been damaged during battle simply threw them away and drew a new weapon from the armory because no one who made supply decisions thought it was worthwhile to manufacture spare parts for the gun.

No wonder it was also nicknamed "the poor man's Tommy Gun."

However, soldiers didn't embrace it at first. The M3 had some initial problems with an awkward cocking handle, but in 1944 the cocking handle was eliminated and a flash hider added – the M3A1.  Once they discovered its stopping power and the weapon's kinks were worked out, GIs and Marines developed a sort of grudging affection for the gun.

It was not only used during the Korean War but also by both U.S. and South Vietnamese troops during the Vietnam War.  U.S. helicopter pilots often carried one in their cramped cockpits because it was smaller than an M16 and offered more firepower than a pistol.

It even developed a kind of "bad boy" reputation because of its prominence in the popular film "The Dirty Dozen." In one famous scene, Lee Marvin's character fires a Grease Gun at the criminals and misfits he is transforming into a fighting unit while they train on an obstacle course.  Throughout the movie, the M3 is carried by most of the cast members.

The reality is the M3 was probably the easiest and least expensive weapon for the movie's armorers to obtain. Yet, the image stuck.

The last time the Grease Gun went to war as an official member of the U.S. inventory was 1991 during Desert Storm. Tank crews carried them as a backup weapon – nearly 50 years after it was first introduced to save money and kill Nazis.