The 17 pdr Gun SP M10 was essentially the 3 inch Gun Motor Carriage M10 with the gun changed for the more powerful 17 pdr. Conversion began in April 1944 but by the 6th June (D Day) only 124 had been converted. Production was increased and by the end of the year 816 had been completed. By the end of the war about 1,100 had been converted.
There is still some uncertainty as to where and when the name Achilles was applied to the vehicle but in service they were generally referred to by their crews as the M10 17 pdr. Depending on which version of the M10 the conversion was based on the designation IC or IIC was added i.e. 17 pdr Gun SP M10 IIC.
Gun
| Mark 6 | Mk 1 with altered breech ring to suit M10 mounting |
Data
| Weight of gun & breech mechanism | 1,822 lbs |
| Total Length | 180.35 inches |
| Length of Bore | 165.45 inches (55 calibres) |
| Rifling | 20 grooves, uniform Right Hand 1/30 |
| Breech Mechanism | Vertical sliding block, semi-automatic, percussion fired |
| Elevation | -5° to +20° |
| Traverse | 360° |
| Recoil System | Hydro-pneumatic, constant, 40 inches |
| Weight in action | 4,624 lbs |
Performance
See 17 pdr Gun page
Carriage M10
See 3 inch Gun SP M10 page