Quote Originally Posted by Fuchs View Post
85 mm was only important in late '43 to '45.
True -- but that's when WW II was 'decided.'
The U.S. insistence on 76 mm for a long time after the war was likely a result of the British great success with the 17 pdr gun (~77 mm IIRC) which equalled the German long (L/70) 75 mm gun in performance which in itself was almost identical to the early war (L/56) 88 mm in penetration. So basically the U.S. was stupid enough to stick for a decade with a gun that couldn't defeat an IS-2 or T-44 head-on and had at most adequate HE effect.
Uh, no. That's rather incorrect...

The US had adopted the 90mm as Standard A in late 1943, production started on the 90 mm M3 towed antitank gun, on the M36 Tank Destroyer and on the M24 Tank. All were in full production when the war ended. The lines were closed at Congressional insistence -- that meant reliance on the many still around but now obsolete M4A3E8s with the 76 up until early in Korea when M24 / M26 production was restarted and by mid '52, the M4s were history.
South Korea would probably be gone if the North Koreans had had T-44's instead of T-34/85s in 1950. The normal (60mm) Bazookas were inadequate against T-44's from almost all angles.
Not likely, most NK Tanks in 1950 were destroyed by Aircraft. The 2.36" / 60mm Rocket launchers were not effective against the T34 unless the Launcher gunner was less than 100 meters away due more to inaccuracy of the weapon than anything else, though few RLs work against any real degree of frontal armor with a decent slope -- glacis plates are thick for a reason. Both better training and the arrival of the 3.5" / 89mm Rocket Launcher (relatively accurate to about 200 m) fixed that by early to mid 1951. In the interim, after September of 1950 when they arrived in theater, after being pulled out of storage, those 90mm Towed AT guns were used with Tungsten hyper shot and they would literally blow a T34 apart.
About 98 mm; funny story. Due to the modern arms limitations treaty (forget the abbreviation, but it restricted all ordnance 100 mm or bigger), there are now a couple 98 mm mortars which are perfectly in between 81.4/82 mm and 120 mm in mortar bomb weight...
This makes as much sense as did all the Washington Treaty light cruisers; 10,000 tons but only 6" guns...
Very little makes much military sense -- too much political involvement...