These are the ones you most likely aren't familiar with reloading. So, here they are!

Cannon/Howitzer/Mortar- First of all, you clean the barrel with a sponge rod. You push it in and out a few times to defuse any sparks or heated gunpowder inside to prevent an accident. Next, you take another rod and pour gunpowder inside. Afterwards, you roll the cannonball into the barrel and push it all the way in with a ramrod. Next, aim the cannon and light the wick to light the gunpowder and there goes the cannonball.

Musket/Pistol/Rifle- You first pour gunpowder into the barrel along with a musketball. Then, you ram the musketball down the barrel with a rod and place gunpowder into the pan. Next, you close the frizzen and cock the flint. Pull the trigger and let the flint ignite the powder as you'll probably  miss!