I have a question about British tanks in 21 Army Group, specifically those armed with 6-pounder guns. I have read John Buckley's book on British armor in Normandy and I know why the British army went to the 75mm instead of retaining the 6-pounder as main armament on tanks. The plan was to have most tanks armed with the 75, which experience in Tunisia and Italy had shown to be the best weapon against German infantry and artillery and which was still just adequate against the Panzer IV. A proportion of tanks (1 in 4) would carry the 17-pounder, which was an even better anti-tank weapon than the 6-pounder and capable of dealing with the latest German tanks and SP's. Units equipped with the Sherman would get the Firefly, while those equipped with the Cromwell would get the Challenger as an anti-tank vehicle. The 17-pounder would not fit in the Churchill and the Black Prince project was dragging on, so a proportion of Churchill III's and IV's retained the 6-pounder to give infantry tank units some AT capability. As we know, things did not work out as hoped in Normandy. The Allies got stuck there for longer than they expected, and Allied armor had to fight German armor more often and on less equal terms than had been anticipated. The Panther was available in quantity and proved to be a nasty surprise. The Challenger was not ready in time for D-Day, and did not reach 21 Army Group until the campaign was well along. I have already alluded to the employment of the Churchill III/IV with the 6-pounder. When provided with APDS, this gun could knock out even a Tiger from certain angles. I have looked at the Trux pages here as well as other sources, and I have found that a small number of Valentine X's with the 6-pounder were employed in subsidiary roles (command vehicle in AT regiments, etc) alongside the Valentine XI. (I am puzzled about that though---Trux says that OP tanks of all types (or some of them?) retained their main armament, while Chamberlain and Ellis say they did not. Who is right?) As far as I know, no early mark Cromwells, Centaurs, or Canadian Rams with 6-pounders were ever used in action. Is that correct? Now, given the problems 21 Army Group was having with German armor and the shortage of Fireflies and Challengers, it seems to me that issuing some 6-pounder tanks to units might have been helpful, at least on a temporary basis until the 17-pounder was more readily available. Was this ever discussed at the time? If anyone has any thoughts or facts about this, I would be glad to hear them.