Here is one thing to try...... He some one load or not load your gun and hand it to you...... So when you aim, gun goes boom or not..... If you 100% don't know if a shell is in the gun..... You will tell right when you pull the trigger if you flinch or not......
I've been with people and used this...... It's an eye opener..... Sometimes on hunting videos they pull trigger gun movers 3-6" and doesn't go BOOM....... OPPs.....
Try it, sometimes it can happen to seasoned shooters.....
Good luck.