Between my father and I.. we've shot over 100 of the new Winchester 777 primers.. and haven't had a single hang fire.

Could be a number of things...

You said that you fired 3 off before ever loading the gun... the primers prolly fouled the hole in the breech plug. Why fire off 3? Did you not run enough patches to clean the barrel? Maybe take a hat pin and make sure the hole in the breech plug is clear of any excess fouling. You should not need to fire off multiple primers to "dry" the breech. These are primers.. not caps. Sounds like you might want to change your shooting regiment... I'm guessing 99% user error...