Reading my book on allied anti tank guns it said that allied command totally misread German tank performance and units available. Anti tank units were mostly armed with the 37 which proved ineffective a few 57s were there but not enough, within weeks 57s were brought in and replaced the 37s but most commands complained that hardly any HE rounds were available. Soldiers would encounter pill boxes or fortified units and needed direct fire HE but hardly any stocks were available. I don't understand why that would be the book stupidly doesn't say why. I would think that if we are mass producing the guns we would have massed produced the ammunition as well. Like if the British needed us to build the gun they couldn't make ammunition for two armies. Also it showed that towed weapons could not cope with mobile units the gun could not be moved fast enough to deal with fast moving enemy tanks and most towed gun positions were over run. Mobile guns did very well and so the anti tank command decided to make all units self propelled. But there were still lots of 57s handed to infantry who had the same problems. The Germans took lots of there light tanks and put big guns on them. We had lots of light tanks we should have mounted the 57 on some of them or the M8 tank replace the 75 pack with the 57. It would have giving troops another mobile tool.