 The tests were finally done on March 25 and May 23, 1944; they seemed to show the 90 mm gun was equal to or better than the 17-pounder.By then, production of the 76 mm-armed M4 and the 90 mm-armed M36 were both underway and U.S. Army interest in the 17-pounder waned.Late in 1944, the British began to produce tungsten sabot rounds for the 17-pounder, which could readily breach the armor of even the Tiger II; these were not as accurate as standard rounds and not generally available.