Are there any cases of a small calibre bullet being fired into an

Cartridge (firearms) - Wikipedia

7mm Rifle Cartridges: The Sweet Spot — Ron Spomer Outdoors

Fireforming. You only get one chance to make good brass.

Is there such a thing as a bullet sleeve that would allow a smaller caliber bullet be fired from a larger caliber rifle? - Quora

How is it determined not only how much internal pressure a gun barrel can withstand but how much pressure a given bullet (lead, copper coated, tungsten, etc.) will create when fired?

Has there ever been a revolver with two circles of bullets, one inside the other, going to two barrels with alternating firing pins? - Quora

The .221 Fireball Cartridge: The Little Round that Can - Shooting Times

Are there any cases of a small calibre bullet being fired into an artillary barrel or tank barrel? Does the shell go off inside the barrel? - Quora

Glossary of Basic Firearm Terms

After firing my gun (pistol) sometimes the cartridge stays in the barrel. Is the problem a substandard bullet or a barrel? - Quora