But it is related to what was the study of high and hyper velocity guns. And it is related to two other developments in .50 caliber and 90mm that I hope to talk about in the future.

All in all, the .50cal, 37mm, and 90mm are both developmental guns and at the same time try and deal with the problems of gun erosion. Because of the difficulties of gun erosion and the refusal of various departments to accept anything less then perfection the US really didn’t end up with a hyper velocity gun until post WW2. That is to say they did not want to accept a gun that could only fire a handful of rounds through its barrel before being toast.

The 75mms on the M10s for instance, despite being a much lower MV could handle 10k rounds before needing a barrel change. The scary thing is new barrels had to be shipped to Italy to replace the old ones because they had all fired some 10k plus rounds of HE in combat.

The gun is basically only one step in a series of trying to make a long lasting hypervelocity gun. Which took years. The British alone spent 10 years, post ww2, perfecting the chrome lining of their 105mm and 120mm guns. Because it tended to wear off the barrel in just a few shots.

You’ll note I’m avoiding the term blank because it means something else for weaponry.

Can we have some real measurement units so that we can compare them to other existing high power 37mm guns?

How is it possible to bore the barrel to a lower calibre? I’d guess you can only refit bore the barrel to have a higher one.