of less than . Due to the initial shock of encountering heavy German tanks, further changes were made in the tank destroyer force in late September 1944. American officials requested that of the 52 battalions then committed to the European theater, 20 be converted to the M36, 20 retain the M10 or M18 at the discretion of their commanders, and the 12 towed battalions be re-equipped with the (then-prototype) T5 90 mm towed gun. By October 1944, the improved 90 mm Gun Motor Carriage M36 began to arrive in Europe, and mostly replaced the M10 by the end of the war. The plans to retain any towed battalions at all were canceled after their generally poor performance and high losses in 1944, especially during the Battle of the Bulge. In the Italian campaign, as in northern Europe, the M10s were normally attached to infantry or armored units as infantry support or mobile artillery, more so the latter because of the general lack of German armor in that theater. Many US divisional commanders asked for their M10s to be replaced with fully armored tanks. In the Pacific war, due to the lack of serious Japanese tank opposition, US Army M10s were not used as tank destroyers, but as mobile artillery and infantry support. The M10 proved unpopular in the Pacific due to its open turret, which left it vulnerable to Japanese close-assault antitank tactics. British Army A total of 1,648 M10s were supplied by the United States to the British Army via the Lend-Lease program. British M10s were designated as 3inch Self-propelled Mount M10 (3-in SPM M10). The M10 with the "wedge" counterweight was known as the "3in SPM M10 Mk I" and the M10 with the "duck bill" counterweight was designated the "3in SPM M10 Mk II". 1,017 of the vehicles were up-gunned with the powerful 17-pounder (76.2mm) gun from May 1944 to April 1945. The designation used within the Department of Tank Design for both the 3-inch and 17-pounder versions was "Achilles". The 17-pounder conversions were designated various ways, with a "C" suffix added on to the "M10" designation, or called "17pdr M10". Most of the vehicles converted were the 3in SPM M10 Mk II, as the duck bill counterweight better balanced the heavy gun. The gun mantlet needed modification to accept the barrel. The 17-pounder was of a similar bore to the 3-inch gun M7, but had a