I have found out that In really cold weather real black powder always goes off, anything else maybe. I have had really bad hang fires with Pyrodex, 777 seams as though it looses lots of power cold. Hunting partner was using 777 couple years ago and noticed that when cold like -20 the gun would shoot about 10 inches low at 100 yds, warm gun and powder up, shoot again and ok. last winter he used Goex black, checked cold and within an inch of when warm. Guess if I,m going to hunt when its really I want my gun and load to be reliable, I'll use black powder.