This mass produced tank destroyer was officially known as the “3-inch Gun Motor Carriage (GMC) M10”.  It is similar in size and shape to the better known M4 Sherman Tank, in part because it was built from the same basic platform.

After the jump, a look at an important American armored fighting vehicle.

US armored doctrine was a little different from most other combatants in World War II. That is partly because we entered the war later than the other major players.  A serious attempt was made to study Blitzkrieg and other armored warfare as doctrine was formulated in 1941-42.

Armament on the M10 was just the 3 inch gun and a flexible .50.

Most significant was the idea tanks were for infantry support, up until a breakthrough situation arose; then the tank was expected to take advantage of the breakthrough opportunity.  The Tank Destroyer was more defensive in nature, and was meant to provide tank killing power, or more specifically, anti-Blitzkrieg power in a tactical reserve.  Tank Destroyers were thus organized in independent commands.  They were meant to be mobile and hard hitting, like a battlefield fire fighting unit.

War time pictures usually show many external stores, but I left this example fairly clean to show the lines of the machine itself.

The M10 specifically was built from the M4 Sherman chassis.  The body was redesigned with lighter armor but better angles.  The turret was also angled with an open top.  It was not powered so traverse was slower.  But the bigger gun (3 inch, or 76.2 mm as opposed to 75 mm in the Sherman) had better penetration from any range.  Initially the armor piercing ammunition was not very good, but this was later fixed.  I’m not an expert on guns, but from what I can tell I think this was a different gun than the 76 mm that was fitted to some later models of Sherman.

In practice, US Tank Destroyer battalions did not act per doctrine very often.  They mostly provided fire support for infantry units and used FAR more High Explosive ammunition than armor piercing.  They seemed to be very well suited for this role, except for the open turret top that was a vulnerability in urban environments.

US tank destroyers were especially uncommon in that they were built from current, contemporary chassis. The Germans in particular most often retasked obsolete designs with bigger guns and heavier armor.  That may have worked out better for their increasingly defensive roles.  While the faster and more mobile types built by the US were more fitting of a nation on the offensive. The M10 GMC, like the M4 Tank it was derived from, was an effective modern unit when it entered service in late 1942; but later it would have problems against newer, heavier German armor.

M4 Tank and M10 GMC.  The family resemblance is apparent, but there are a lot of differences too.  

The M8 Armored Car, M4 Tank and M10 GMC were very common American AFVs for the war in Europe.

This example is the Tamiya kit. It represents a vehicle that fought in France during the hedgerow campaign of July, 1944.  This was a period of stalemate after the Normandy invasion when US and British forces built their strength for a large breakout operation.

Panzer III and Panzer IV on the left were the main German types when the M10 entered service in North Africa.  The M10’s 3″ gun could defeat either tank easily.  But when the Panther and Tiger started arriving in greater numbers from late 1943 the 3″ was inadequate for the challenge.

Differences in American and German philosophies for Tank Destroyer design.  The Hetzer and Marder III at right were re-tasked from obsolete platforms, while the M10 was built on the current M4 Tank.