FYI. The shooter in the "wannabe" video was not trying to demonstrate tactical shotgunning. He was just function checking his new 590 Mariner. He loaded three at a time because the public range had a three round rule.
Use at your own risk. Past performance is not a guarantee of future results. This could lead to serious injury or death. Void where prohibited. For entertainment purposes only. Cheer up. There is a chance that my info could actually be helpful.