I own two and both are tack drivers at 100yds using pyrodex and 250 gr SSTs. I have not tried 777 in them. I bought them just to shoot at the range but they are permitted during hunting season here in VA. I like them and am not worried about parts in the future as I bought them for 120 and 130 bucks from Sportsman guide with free shipping. To me they are fun to shoot and as an electronics engineer I think it's pretty cool they use a circuit and battery.