Why a shell must match the gun and fuze arrangement

What matters when firing a standard 6-inch or 105 mm high-capacity shell through a different weapon?

The shell's engagement with the barrel and its fuzing must be compatible, or it could detonate in the gun.

Firing a standard large high-capacity shell through a different weapon requires attention to how the projectile engages the barrel and how its fuze behaves. A mismatch could cause the shell to detonate inside the gun. These compatibility questions come before estimating the proposed shot's performance.