The desire to mount the 17 pounder on the M10 was governed by the degree of difficulty involved in mounting the 17 pounder on the tank itself.
Luckily for the British, the initial batches of M10s had an easily modified gun mounting to facilitate the future replacement of the older 3 inch M7 gun with the newer 76 mm gun M1.
This gun mounting design allowed for the British to replace the 3 inch gun with the 17 pounder gun.
The British took delivery of some 845 vehicles in 1943, but of the second version of the M10, only the T71 mark designed to carry the M1 gun could carry the 17 pounder.

The British had planned to convert some 1,000 M10s into 17pdr armed variants for Normandy, but for some reason conversions were not started until April 1944.
By D-Day, only some 124 M10s had been converted; however, the number of conversions post D-day increased and by the end of the year 816 M10s had been converted, 152 vehicles in November alone.
However, the low numbers at D-day meant both that many British units went ashore fielding standard M10s and losses in Achilles units were often replaced by standard 3" armed M10s.

As a self-propelled anti-tank gun, both Achilles and standard M10s were distributed to and operated by the regiments of the Royal Artillery.
Around 1,650 M10s were received by the British during the war, with 1,100 converted to the 17 pdr by its end.
The desire to mount the 17 pounder on the M10 was governed by the degree of difficulty involved in mounting the 17 pounder on the tank itself. Luckily for the British, the initial batches of M10s had an easily modified gun mounting to facilitate the future replacement of the older 3 inch M7 gun with the newer 76 mm gun M1. This gun mounting design allowed for the British to replace the 3 inch gun with the 17 pounder gun. The British took delivery of some 845 vehicles in 1943, but of the second version of the M10, only the T71 mark designed to carry the M1 gun could carry the 17 pounder.
The British had planned to convert some 1,000 M10s into 17pdr armed variants for Normandy, but for some reason conversions were not started until April 1944. By D-Day, only some 124 M10s had been converted; however, the number of conversions post D-day increased and by the end of the year 816 M10s had been converted, 152 vehicles in November alone. However, the low numbers at D-day meant both that many British units went ashore fielding standard M10s and losses in Achilles units were often replaced by standard 3" armed M10s.
As a self-propelled anti-tank gun, both Achilles and standard M10s were distributed to and operated by the regiments of the Royal Artillery. Around 1,650 M10s were received by the British during the war, with 1,100 converted to the 17 pdr by its end.
17pdr SP Achilles