Have you tried to shoot blanks with 777?
If you have done so successfully, please share your impressions and your techniques.
I lovingly craft my own 1.125" lead balls and shoot them at every opportunity, but I shoot a LOT more blank loads than live rounds. If I could not shoot blanks, me, my friends, and my family would be missing out on a lot of fun.
Holidays especially. A casual backyard gathering is no place for dangerous projectiles. Even a blank salute charge at a social gathering requires strick attention to safety, but it can be done safely and sure adds to the occasion. Kids love to see a real cannon go bang! They want the noise, the fireball, and the thick stinky smoke.
But in fairness, 777 was not around when I was experimenting, so I have no experience (good or bad) with that product.