Largest gun that will fit on a tank

So I was looking at our glorious Spacebattles logo and noticed the tank barrel on that image is a lot longer than I remember it being on the T-34-85. Which got me thinking, what's the largest gun

America's T-28 Was America's Biggest (and Ugliest) Super Tank

The largest tank in the world #foryou #fyp #foryoupage #science #popul

The U.S. Army Wants to Put Big Guns on Small Tanks

What tank has or had the largest gun? - Quora

What is the largest caliber gun ever to be fitted onto a tank? - Quora

Special Rules – GF9 World of Tanks

Panzer VIII Maus - Wikipedia

Military Armed 8 in 1 Tank Building Blocks Set, Compatible with Lego WW2 Armed (642PCS) Toys Gift for Boys 6-10, 8-14 Year : Toys & Games

landkrueser p1000 RATTE (the largest tank ever designed) made in blender :( : r/TankPorn

Tim Mee Dominator BIG TANK for Action Figures 22in long Olive Green – BMC Toys

What is the largest caliber gun ever to be fitted onto a tank? - Quora

What tank has or had the largest gun? - Quora

Largest gun that will fit on a tank