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.

Firstly the sticks have more reports of problematic ignition compared to the loose APP 3F powder which is potent and reliable.
Secondly the primer should be fresh and the gun needs to be properly stored and sealed at both ends to keep moisture out between cold weather hunts and until it's discharged.
That includes protecting the bore from condensation.
The cold temperature shouldn't negatively affect anything if all is properly stored and sealed.
If there was a partial flash hole blockage then that's not a cold weather issue per se, but could have contributed to the problematic ignition due to the reasons above.

I'll never have to worry about that. At -20 my hiney is going to be inside by a fire.

Amen brother lol.. Amen.. Ray

Who makes the hiney? What caliber is it? How does it do with the newer powders? Is the breech plug removable? When one removes the breech plug does it require a tool? Does one need an FFL to mail it?............................................... ......................

You'd have to be a tool to remove the BP.

Thanks for all the replies!

I plan to switch to Pyrodex. I only used Shockley's square sticks cause that is all that was left at the gun shop right in season. Also will switch to muzzleloader primer caps - I would suppose they burn hotter than regular reloading primer caps I was using.

Interesting comments on blackpowder vs. pellets. Sounds like powder is more accurate. And I think the round 777 pellets are better than the square sticks I used.

The muzzleloader specific primers are mild. In cold weather I would use a regular strength 209 primer such as Win209, Rem STS, CCI.

Amen to that! Although I've never been in -20 weather in my life and hope to never be. Hell is not a burning hot place, it's a bitter cold place and the wind blows constantly.

That's not hell; that's Montana.