What happens next?

How to load a shotgun
Make sure the safety is on, the chamber unloaded, and the barrel pointed away from you in a safe direction.
This is always the first step when loading or handling any gun. Consult your weapon's instruction manual to locate the safety feature.

OPT:
[I] Insert the correct size ammunition into the chamber. Hold the correct weight in both hands when you insert the ammunition..
[II] Determine what gauge (bore diameter) your shotgun is so you can select the right size shells. Common shotgun sizes are 10 , 12 , 16 , 20 ,..
[III] Since you will be taking an even more drastic measure with your handgun, take the time to familiarize yourself with different types of magazines and settings if you intend to take an aggressive route. De-pressurize your newly loaded gun or clip..
[IV] No-shoot only, unless directed otherwise by the manufacturer. At that point, you will be moving your finger on the trigger..
[II]