17pdr SP M10 "Achilles"
M10 Achilles self-propelled anti-tank gun with its distinctive long-barreled high-velocity British 17pdr, at La Roche-en-Ardenne, Belgium
Type	Self-propelled anti-tank gun
Place of origin	United Kingdom
Production history
Manufacturer	Fisher Tank Arsenal Grand Blanc, Michigan - converted by Royal Arsenal, Woolwich
No. built	1,100
Specifications
Mass	29.6 tonnes (65,000 lb)
Length	7.01 m (23 ft 8 1⁄4 in) including gun 5.97 m (19 ft 7 in) excluding gun
Width	3.05 m (10 ft)
Height	2.57 m (8 ft 2 in)
Crew	5 (commander, loader, gunner, loader's assistant, driver)
Armour	9 to 57.2 mm (0.3 to 2.3 in)
Main armament	Ordnance QF 17 pounder (76.2 mm) 50 rounds
Secondary armament	.50 cal (12.7 mm) Browning M2HBAA machine gun 420 rounds .303 (7.62 mm) Bren light machine gun[1]
Engine	General Motors 6046 diesel (twin 6-71) 375 hp (276 kW)
Power/weight	12.5 hp/tonne
Suspension	Vertical Volute Spring Suspension(VVSS)
Operational range	300 km (186 mi)
Speed	51 km/h (32 mph)

The 17pdr SP Achilles (officially 17 pounder, Self-Propelled, Achilles) was a British variant of the American M10 tank destroyer armed with the British Ordnance QF 17 pounder high-velocity 76.2 mm (3 inch) anti-tank gun in place of the M10's considerably less powerful 3 inch (76.2 mm) Gun M7. A total of 1,100 M10s were converted to Achilles, making it the second most numerous armoured fighting vehicle to mount with the 17 pounder gun, behind the Sherman Firefly.

The name "Achilles" was officially a designation applied to both the 3" gun and 17 pounder versions (as Achilles I/II and Achilles Ic/IIc respectively) but was little used during the Second World War; at the time, the vehicle was called 17pdr M10, or 17pdr SP M10, or even occasionally, "Firefly". It has since become identified almost exclusively with the 17 pounder version.