The M10 GMC: The first good American TD

M10 GMC: Good, but not Great, It got the Job Done

The M10 was a tank destroyer mounting a 3-inch anti-tank gun and was known as the M10 3 inch Gun Motor Carriage during the war, or M10 GMC. It used the M4A2 chassis with the GM 6046 to power it, with a new lighter upper hull and turret. These tanks only had an M2 .50 caliber machine gun other than their main gun. The turret lacked power traverse. It had a five-man crew and was generally liked by its crew.

The American TD force was deemed a failure, but not because the men or vehicles performed badly, it was the doctrine that failed to pan out, the battalions themselves performed well overall. It was used until the end of the war, and many TD battalions preferred it over the faster M18.  The TDs lacked a co-ax machine gun, this and their open top made them more vulnerable to infantry than a tank. Even so, these units were often given tank missions. The open top did offer a big advantage in finding any enemy tanks to shoot though. ⇓

One aspect of the design that shows how rushed it was are the driver’s hatches. They were larger than the Shermans produced at the same time, but could not be opened or closed if the turret was forward. So the crew had to make a choice if the driver and co-driver were going to be able to see well or be buttoned, before the battle or movement.  The M10 lacked a turret basket, so the driver and co-driver had an easier time getting out of the roofless turret. Like all American designs, it went through a series of upgrades through its service life. The turret was upgraded and balanced better, and the crews liked to add their own roofs.  A power turret drive was never added to the tanks in US service though.

The M10A1 version of this vehicle had a Ford GAA motor. There was no difference other than the changes needed to manage the Ford GAA instead of the GM 6046. Crews added on armored roofs to their turrets, often all hinged so they could open up to really see what was going on, in the field. It was not uncommon for TD units to be used as fixed artillery for several days.

The M10 Turret went through several changes, the first versions were badly out of balance, and they tried to solve this by mounting the grousers for the tracks on the back of the turret. This didn’t work well and wedge-shaped counterweights were added. This helped, but eventually, the final production M10 turrets were widened, and even bigger counterweights were added with a distinct duckbill look to them.  They came up with a full roof armor kit for the final turret, and a half cover for the early turrets that could be field retrofitted.

The M10 and M10A1 had all the gear aboard to be used at artillery, and they got used in this role on a regular basis. A few TD battalions spent almost as much time as artillery as they did in their TD role. This capability was used often in Italy because the 3 inch gun on the M10 didn’t tear up the vital roads as much as the larger guns did.

They built 4993 M10s and 1713 M10A1s. At first, only M10 TDs were authorized for service overseas, and the M10A1, even though found to be automotively superior, was to be used in stateside training only. There was some doubt about the usefulness of the motorized TD before the Normandy landings, and production of the M10 was halted as many TD units were converted back to towed gun units or disbanded.

The M10 saw action in North Africa, Sicily, Italy, and Northern Europe, and various Pacific Campaigns, the most notable being the retaking of the Philippines. It wasn’t really until the action started after the Allies went into Normandy that it really saw a lot of anti-armor use. In the MTO the TD units spent an awful lot of time being used as artillery units, to the point they had to learn how to swap barrels on their 3-inch guns after wearing the tubes out.

The M10 in northern Europe saw lots of action but was also being replaced by the M18 and M36. The M36 was very popular, the M18 was mixed, some units love it, some units refused to give up their trusty M10s. The M10 was not popular in the Pacific, the thinner armor, lack of hull and co-ax machine guns and open top made for a much easier target destroy for Japanese troops.

If you are wondering what the little round pads all over the M10 are, they were for an armor add-on kit, that was never used for some reason. They gave the crews a handy place to hang other things though, like bags and camo nets…

♠ M10 GUN and Vehicle DATA ♠

Click on the below links to get PDF version of the spec sheets.

3 inch M7 gun GMC M10 Spec Sheet,  M10 GMC 3inch spec sheet

♠ M10 GMC Gallery ♠

An M0 Wolverine on the move in St Fromond France. The M10 is with the 703 TDB attached to the 3rd Armored Division.
A pair of M10 TDs supporting the 30th Infantry in Magdeburg Germany in 1945
A pair of semi-early M10s with wedge-shaped counterweights on the way to the front in Tunisia, 1943
An M10 or M10 A1 supporting the 77th Infantry Division on Leyte 1944
An M10 with the 803rd TDB in Ubach Germany, this M10 is clearly knocked out, at least two hits to the front, the black line is a from the censors. 
M10 TD moving through Speicher in 1945 supporting the 76th ID
An early M10, maybe at the Ford plant.
Another M10 supporting the 77th ID on Leyte in 1944, M10s in the Pacific seems like rough duty, in particular, if you think about how the tankers in Shermans operated buttoned up!
M10 supporting the 32nd ID near At Aitape New Guinea, I had no idea M10s had been used in New Guinea, one of the few places in the world there are still Cannibals in the jungles.
An M10 with the 893rd TDB moving down a snow and mud covered road in the Hurtgen Forest
Late production M10 supporting the 77th ID near Ormoc in the Philippines 1944
An early M10 with the 454th TDB knocked out during the fighting at the beginning of the Battle of the Bulge
This is an M10 entering Fresnes France in 1944, unit known.
An M10 moves into Artena Italy in 1944, unit unknown.
This image shows a repair crew fixing an M10 damaged by artillery or mortar fire near Anzio, Italy 1944, note the railing welded to the add-on armor points. 
An Army M10 somewhere in the PTO probably in the Philippines.
An M10 supporting US troops entering Fontainbleau France in August of 1944
An early M10 heading to the fighting near Bir Marbott past, east of El Guettar Tunisia, in 1943.
M10 in the French town of Givenchy En Gohelle near Calais France, 1944
M10 tank destroyers rolling out of the Ford Factory in Detroit, 1943.
M10 and M4A3 Shermans being built side by side at Fords plant in 1943
Another shot of the Ford M10 line in 1943
An M10 supporting the 2nd Armor Division near Tesey Sur Vire France, 1944
An M10 with the 803rd TDB in Ubach Germany late 44, the black mark is from a wartime censor, not damage, though the M10 is clearly burned out4. 
An M10 with the 773rd TD Battalion, supporting the 90th ID near Mainz Germany in 1945
30th ID doughs ride on 823rd TDB M10 in Germany, 1945
This is an M10 in the Pacific, the crew is cleaning the gun, and the TD is with the 632 TDB on At Aitape
M10 of A Company, 645th TDB, Supporting the 157th Infantry Regiments, in the Town Of Niederbronn France
M10 in Percy France in 1944
M10 in Aachen 1944
M10 serving with the Algerian Free French 3rd Division in Omia Italy in 1944, note the improvised roof
An M10 near Halloville France, November of 1944
M10A late production M10 with duckbill counterweights and wading trunks engages targets in France.  It is supporting some doughs, the black marking on the left rear hull is scratch made by a wartime censor to keep the units identity secret.