The 76mm HESH is a good round, but more tho the point, Sov export tanks, T-72's in particular, were crap! When 1990 rolled around, and everybody was worried about Saddam's huge army, our gunnery guys were working on a long rod penetrator APDSFS (more mass) and it would blow right on through 3 T-72 turrets lined up front to back.
The Americans were working on a 140mm gun for the Abrams, and versions of the 155mm howitzer for a gun tube. They found out that they didn't need them. Even the Marine Corps M-60 A3's with their 105's were good enough (just weak on the armour side.)
The 120's that we have now, using the L55 gun tube in the Leo 2, and the Challenger 2's 120mm L32(?) are absolutely the kick ass guns of the day. The Abrams' gun tube is still good, but has less muzzle velocity than the other 2. The Russian 125's have always shown themselves to be lacking in hitting power.
I met a sergeant in a tank battalion who exercised through CFB Wainwright in Alberta one year, and he was in the Gulf War (1991). A T-72 sabot hit one of their tanks in the turret front, left side, and stuck there. They left it until they could get back to a servicing area, and the techs just cut it off flush and left it in the armour. When it went back to the States, it went to the Lima tank armory and was studied for awhile.