- Pzkpfw-e
The Pak 97/38 used a HEAT round.
I guess the lack of a HEAT round for US 75mm guns, reflected the doctrine that 75mm gun tanks, shouldn't be used in an antitank role?
Doesn't really make sense as they had several different other types of armour piercing ammunition?
The M66 was fired at a mere 300 m/s, which would probably make it rather inaccurate for anti-tank work. Penetration was about 85mm, which was better than standard AP, but not enough to deal effectively with Panthers and Tigers in situations where the standard AP could'nt do the job.
If US HEAT was anything like the German variety, it did not perform well at anything other than ideal conditions either.
So probably not worth the trouble. Particularily as more and more US tanks were made with larger guns at the time HEAT became available (assuming 1944-45?).