We’ve all seen it in the movies and read about in it Medal of Honor citations. A Soldier or Marine throws himself on a grenade to save his battle buddies. It is seen as the ultimate act of self-sacrifice. In the Pacific theater, no less than 27 Marines were decorated for throwing themselves on top of grenades. Most of the men who did this did not survive. But four did. You see, not all grenades in WWII were made alike or used for the same purposes.
Believe it or not, grenades come in offensive and defensive types. Offensive grenades have larger explosive charges at the expense of fragmentation weight and allow the user to throw the grenade and not be killed or wounded by its shrapnel.
A defensive Grenade is one in which the blast radius is smaller but its shrapnel range (20-30 yards) makes it as lethal to the thrower as it is to his intended target. After these types of grenades are thrown, the user must be behind a hard cover to protect himself from sizzling iron shards moving 700 feet per second in all directions.
Japanese grenades were of a pineapple fragmentation type with two ounces of explosives inside of them. They came in two models: Type 91 and Type 97. The 91 had adaptors on it so it could be fired from a rifle or small mortar, while the 97 was strictly for hand throwing. The fuse was a pin type that required a hard strike on a solid object to ignite it. In the battlefields of the Pacific, Soldiers and Marines learned to listen for the sound of a grenade being struck against the helmet of one or a dozen Japanese soldiers about to attack them with grenades. Both types were known to be weak in terms of explosive power and tended to produce very small fragments. They were considered offensive grenades which allowed Japanese troops to throw them en mass and then rapidly advance as they exploded in the enemy positions. Japanese troops grew to be distrustful of Type 97 as a shoddy fuse design tended to cause non-detonation in the humid jungles of the Pacific, or premature detonation as soon as the pin was compressed.
Russia fielded the UZRGM (Universal Igniter, Hand Grenade, Improved) F1 type grenade. This grenade was an offensive type copied from the French grenade of the same name. Very similar to the U.S. MIIA1 type, it was lethal out to about 20-30 yards while fragments could still wound out to 200 yards. It held a two-ounce explosive charge. An interesting feature of the Soviet version of this grenade is that it was designed for a left-hand pull of the pin and a right-hand throw. As is so common with weapons of the Soviet Union it was produced in such staggering numbers that it’s still in use today. Troops in Afghanistan and Iraq have both reported F1 grenades being chucked at them by the enemy.
The British fielded the Mills Bomb No36M MKI which, like most of the grenades mentioned above, dates back to WWI. Inveterate tinkerers, the Brits kept improving its design and continued making it into the 1980s. In WWI and WWII the British Army believed that the throwing arm of Cricketers made for the best grenadiers and sought them out for the role of Bomb Throwers.
The WWII Mills Bomb had a shellack coating to make it water-resistant and protect its fuse mechanism, the most vulnerable (and dangerous) part of a grenade. The British made tens of millions of these grenades well into the 1980s. It saw wide distribution to countries allied with the U.K. like India and Pakistan. In 2004, Marine Medal of Honor awardee Jason Dunham threw himself on a Mills Bomb in Iraq to protect his squadmates. He did not survive.
In WWII, the U.S. military fielded the MIIA1 fragmentation grenade as its primary grenade. It was considered a defensive grenade type because it was designed for maximum fragmentation effect at close range. Like the Soviet F1, the MIIa1 was also a copy of the French design. And it was very effective. Having a charge of only three-quarters of an ounce of black powder inside, the slower internal detonation ensured the breakup of the iron body into thumbnail-sized fragments that were lethal out to 30 yards. Injury from these fragments could extend out to a full 200 yards, making the MIIA1 a pretty deadly grenade.
These grenades were thrown football style, with the fuse end trailing and hopefully producing a spiral effect when thrown. Initial inventory at the start of the war tended not to go off at all but the new stock delivered to U.S. forces all over the world proved to be very reliable. Even German and Japanese troops prized these grenades, which is something they could not readily say about their own equipment. As effective and iconic as the MIIA1 was, in the Pacific, Marines preferred the larger and more concussive Mark IIIA2 to clear bunkers and caves since Japanese troops tended to stay dug into defensive positions.
Finally, we have the German Model 24, Steilhandgranate, or “stick handle grenade.” Also known as the “Potato Masher” by Allied forces. This grenade was an offensive type containing a charge between six and seven ounces for a large, concussive blast effect but its thin-walled canister produced very little shrapnel. This was in line with German infantry tactics at the time, which consisted of using these grenades to stun and shock enemy troops in a trench or emplacement until German troops could rush the position and overwhelm the defenders. Its very large size made it a bit unwieldy for an infantryman to carry but, among grenades of WWII, it was unmatched for throwing distance.
Gripping the bottom of its wooden handle and throwing it the grenade would spin in the air. With practice, the soldier could drop it on top of a target with great precision. There were several instances in WWII where German and American troops chucked grenades at each other at ranges under 50 yards. The Americans found that the Steilhandgranate’s concussion was indeed stunning while the Germans found the U.S. grenade was more lethal when it exploded. But the Potato Masher could be thrown farther and with better accuracy. In an enclosed space it was especially deadly with its whopping six-seven ounce charge, which could kill a man with the overpressure of the detonation. But there are numerous reports of the stick handle grenade going off just feet from U.S. troops in the open without them being seriously harmed. Outside of an enclosed space, it’s concussive power was mostly wasted.
The Steilhandgranate represented the operational philosophy of the German Army in the 1930s which held that the next war would also involve trench warfare and battles over towns and fixed fortifications. In such environments, an offensive grenade with a concussive punch would be useful. That was the war the Wehrmacht fought in France in 1940. But from there they went on to fight in the deserts of North Africa, the Italian mountains, and the vast steppes of Russia where this grenade was not very effective.