There are of course different low recoil large calliber guns for lightweight platforms. For example 105mm M68A2, 120mm RUAG CTG or 120mm XM360 and many more.
Low Recoil XM360/L48 120mm smoothbore gun for lightweight platforms, and XM360E1/L48 120mm smoothbore gun for Main Battle Tanks, notice that XM360E1 being a tank gun, does not need muzzle break.
M1128 MGS Stryker's armed with M68A2/L52 low recoil 105mm rifled gun. Notice that contrary to prototypes, M68A2 do not have muzzle break, just like it's predececors M68A1 (used on M1 and M1IP Abrams tanks) and M68 (used on M60, M60A1 and M60A3 tanks).
My personally favourite's the Sprut-SD & I feel it's quite underrated. A 125mm cannon on such a compact chassis. Only & major drawback.... too lightly armored. But then again it's compact, air-droppable, can swim, has the biggest gun amongst all light tanks ; ) & packs an autoloader.
b.t.w. does anyone have any interior photos of the Sprut ? Thanx in advance.
Actually calliber of main gun is not the main factor making vehicles firepower effective, especially anti armor firepower.
2S25 Sprut-SD use very similiar autoloader design to T-72/T-90 tanks, this means that there is a limit of APFSDS penetrator lenght, that reduces it's effectiveness in case of MBT's front armor, and in some cases also side armor when it is also up-armored.
However 125mm smoothbore gun, will probably have more effective HE ammunition.