Users should match the caliber, or the measurement of the diameter, of the bullet with the caliber of the rifle or other firearm. Otherwise, there may be a significant risk of misfires, which can result in damage to the gun and the user.
The larger the caliber of the bullet, the larger the game for which the bullet is used. Smaller caliber bullets are typically used for varmints and predators, depending on their sizes. Larger bullets can be used for smaller game, but they are more expensive to purchase, so users may choose to save larger bullets for tougher game, such as moose and bears.