cayuga
BH209 is the only powder i use for hunting. Actually, BH209 is the only powder i use. When i get a shot at a critter, i always reload immediately, because of an experience i had years ago, when i walked up to a 'dead' deer unarmed, and had to 'steer wrestle' it, and cut it's throat.
Every time i have ever shot anything with a muzzle loader, it has been dead when i arrived at the kill site. So, when i come home, my rifle is loaded, and i leave it that way in the cabin of my pick-up. I have left my rifle over night many many times there in the truck. Some nights it has been 40*, and other nights it has been -19*, and other nights something in between. I don't take any special steps to 'store' my rifle when i get home; it rides home with me, and when i go into the house, it stays where it was when we finished hunting, rode home, and drove into the driveway
My Omega has never failed to fire the next day.
I have hunted in rain, snow, wind, and beautiful blue sky days. My Omega has never failed to fire. I use electricians tape twice over the muzzle when i hunt.
Winchester shot gun primers is what i have been using, because that is the only primer i could find locally when i started, and i wasn't interested in deviating later on because my rifle was sighted in, and i was ready to hunt.
This year i tried out an Accura, and i have had a hang fire, and a no fire with this rifle. I think it has to do with the shape of the breech plug. The Omega breech plug has a deep concavity in the face; the Accura breech plug has a very shallow concavity. I plan on using a hotter primer in the Accura when i find some.
In conclusion, i have to say that BH209 is 100% reliable in the Omega, in all kinda weather, whether it be hot, cold, warm, dry, wet, or snowy. I do not clean the rifle for weeks during the hunting season. When i notice there is more blow back than normal, i drill out the carbon in the breech plug, and hunt some more. I don't use teflon tape or any anti-seize grease.
I personally believe that if one uses BH209, and does not clean the rifle after arriving home, one should never never never use traditional muzzle loader lubricants and solvents. I believe those that have reported rusting issues with this powder, did not use lubes and solvents intended for center fire rifles, which they should have, per the manufacturers recommendations.
Normally i don't shoot my rifles when it is hot, so i can't really report on BH209 used during the heat of summer.