As a result, half of the battalions converted to towed, 76-millimeter M5 guns similar in effectiveness to the M10’s own gun. These supplemented the companies of lighter 57-millimeter guns integrated in each infantry regiment.

As tank-destroyers were drawn increasingly into infantry support roles that exposed them to artillery and infantry fire, their crews piled sandbags on top of them in order to detonate Panzerfaust anti-tank rockets. Other field-modifications included additional machine guns and even armored panels covering the tank-destroyers’ vulnerable open tops.

The arrival of new Sherman tanks in 1944 sporting their own 76-millimeter guns further blurred the distinction between tank-destroyers and tanks. There were now Sherman tanks just as effective at tank-hunting.

Busting Panzers in Normandy:

Tank-destroyers fought in two major engagements in Normandy in addition to numerous smaller skirmishes. On July 11, 1944, three panzer battalions of the Panzer Lehr Division, supported by mechanized infantry, launched a counterattack to relieve Allied pressure on the city of Saint Lo.

The two wings of the attack ran into dispersed M10 platoons of the 799th and 823rd Tank Destroyer Battalions near the village of Le Désert, supported by abundant air power. In a series of sharp engagements in the claustrophobic hedgerow corridors of the Normandy countryside, the Panzer Lehr division lost 30 Panther tanks.

Three weeks later, four panzer divisions attempted to pinch off the Allied breakout from Normandy in the Mortain counteroffensive. The Panzers ran into the towed guns of the 823rd Tank Destroyer Battalion. In the dense early morning fog of the opening engagement, the 823rd was forced to fire at the muzzle flashes of equally-blind Panther tanks.

Unable to pull back the entrenched weapons, the 823rd lost 11 guns but succeeded in taking out 14 tanks. Self-propelled tank-destroyer battalions rushed into help. U.S. forces held Mortain and the German armies in northern France collapsed into a full retreat.

New tungsten-core, high-velocity, armor-piercing ammunition began to arrive for the 76-millimter guns in September 1944. The new rounds could reliably pierce German armor at range. Each Wolverine received only a few rounds of the rare ammunition, but it at least gave them a fighting chance at penetrating the German heavies.

Eleven tank-destroyer battalions were designated “colored” units. They were manned by African-American enlisted men and, mostly, white officers. The third platoon of the 614th Tank Destroyer Battalion, equipped with towed guns, won a Distinguished Unit Citation for beating back a German infantry counterattack after losing three of its four towed guns.

Its commander, Lt. Charles Thomas, stayed to direct the fight even after his M20 scout car was knocked out and his legs were raked with machine-gun fire. He was awarded a Distinguished Cross that was upgraded to a Medal of Honor in 1997. By contrast, the 827th Tank Destroyer Battalion was infamously plagued by poor leadership.

M10s and M18s also saw action in the Pacific, serving notably at Kwajalein Atoll, Peleliu, The Philippines and Okinawa. Facing only limited enemy armor, they specialized in destroying Japanese pillboxes, though some apparently took out tanks in the Battle of Saipan.

More than 1,600 M10s would also serve in Royal Artillery anti-tank regiments of the British Army. Almost two-thirds were eventually given extra armor plates and up-gunned with the superior 17-pound anti-tank gun, and were known as M10C Achilles. The 17-pound — also 76 millimeters in caliber — was a reliable Tiger- and Panther-killer. British doctrine treated the Achilles as a fast-deploying defensive weapon rather than as an active tank-hunter.

The Achilles acquitted themselves well. In a battle near Buron, France, they knocked out 13 Panzer IV and Panther tanks for the loss of four of their number. They often escorted heavily-armored Churchill tanks that lacked adequate anti-tank firepower.

Some 200 Wolverines served in the Free French Army, where they were well-liked. Famously, the French M10 Sirocco fired across the two-kilometer-long Champs-Élysées boulevard of Paris from near the Arc de Triomphe to knock out a Panther tank at the Place de la Concorde.

Even the Soviet Union operated 52 M10s received through Lend Lease. These served in two battalions that saw action in Belarus.

The New Blood:

In 1944, two additional tank-destroyer types entered service. Buick designed the M18 Hellcat for pure speed. Lightweight and powered by a radial aircraft engine, it could zoom along at 50 miles per hour in an era that tanks rarely exceeded 35 miles per hour.

However, it had only an inch of armor and was armed with a 76-millimeter M1 gun that was little more effective than that on the M10. Several units in Italy refused the upgrade to the M18 — armor was more important than speed in the cramped mountainous terrain. But the M18 was popular in Patton’s hard-charging 3rd Army.

While speed is useful for getting armored vehicles where they’re needed, accounts differ as to whether it provided the M18 much benefit at the tactical level. An Army study concluded it was unimportant in tactical combat. Other sources maintain the Hellcat’s speed enabled it in using hit-and-run tactics.

The M36 Jackson — or Slugger — on the other hand, had the hull of the M10 with additional armor and finally upgraded the armament to a heavy 90-millimeter gun. Not only were the heavy shells effective Tiger- and Panther-killers at long ranges — one once knocked out a Panther nearly four kilometers away — but they were significantly more effective against infantry.

2,324 were converted by the end of the war from various M10 and M4A3 vehicle hulls.

The new tank-destroyers acquitted themselves well in combat. In the Battle of Arracourt, two platoons of Hellcats — eight in total — from the 704th Tank Destroyer Battalion moved swiftly into ambush positions behind a low ridge on a foggy day, only their turrets poking over the rise.

When a battalion of Panther tanks from the 113th Panzer Brigade entered their sights, they knocked out 19 for the loss of three of their own number. At the Siegfried Line, M36s excelled at knocking out fortifications and helped beat back Tiger tanks that had decimated Shermans of the 9th Armored Division.

The Battle of the Bulge, a massive German counteroffensive in the frozen Ardennes forest, was the swan song of U.S. tank-destroyers. The Hellcats of the 705th Tank Destroyer Battalion helped the 101st Airborne repel German armored assaults at Bastogne.

A detached platoon of M18s escorting Team Desobry helped take out 30German tanks in Noville. M36 Jacksons of the 814th Tank Destroyer Battalion took 50-percent casualties in a delaying action at Saint Vith, knocking out 30 Panther tanks in the process.

The towed tank-destroyer battalions didn’t fare so well. Several battalions had to abandon their guns in the face of the German advance. Others got stuck in the mud and snow. While M10s of the 644th Tank Destroyer Battalion destroyed 17 tanks in two days in the ill-fated defense of Elsenborn ridge, the towed guns of the 801st fighting in the same battle lost 17 guns.

Of the 119 tank destroyers lost in the Battle of the Bulge, 86 were towed guns. Meanwhile, the tank-destroyers claimed 306 enemy tanks. In January 1945, it was decided to re-convert the towed units to self-propelled battalions.

By the end of the war, the writing was on the wall for the tank-destroyer — particularly when the first of the early M-26 Pershing tanks armed with the same 90-millimeter guns as on the M36 began to see action in early 1945.

Tank-destroyers were pretty much just tanks with inferior armor and better guns. Contrary to doctrine, commanders in the field asked them to perform most of the same tasks as regular tanks. Why invest in a whole separate branch of the army and different class of vehicles when you could simply give tanks the same gun?

Just three months after the end of World War II the Army disbanded the tank-destroyer branch. While the U.S. military did develop a few more specialized anti-tank vehicles, such as the M56 ONTOS, Army doctrine would go on to assert “the best means of taking out a tank is another tank.”

World War II was not quite the end of the line for U.S. tank destroyers. The M36 Jackson and its 90-millimeter gun were hastily called back for use in the Korean War five years later to counter North Korean T-34/85 tanks.

Surviving tank destroyers were resold all over the world. M10s and M18s saw action with the Nationalist army in the Chinese civil war. Wolverines cropped up in the Arab-Israeli conflict and Pakistani M36s battled Indian tanks in 1965. Croatia and Serbia used M36s and M18s in the Yugoslav civil war of the early to mid-1990s. Yugoslavia even deployed M36s as decoys against NATO airstrikes during the Kosovo War. Upgraded M18s remain in Venezuelan service today.

The shortcomings of U.S. tank destroyers are clear. They were intended to fight in a specific context that largely failed to materialize. They had inferior armor protection. With the exception of the M36, they weren’t reliably capable of taking out the scariest enemy tanks.

Post-war Army historians roundly lashed them for these shortcomings. Yet here’s the funny thing. Operational records show that the tank-destroyers actually rocked.