Please discuss, and follow the side trails, I would like to get this right the first time.
What I have is A) a chronograph only rated down to +20dF B) a Redhawk in 45 Colt, and C) hangfires and squibs with H-110 between +30dF and 0dF.
I noticed last year that I too have trouble lighting H-110 when I leave the ammunition in the trunk of my car for a few days to cold soak before I try to light it. I am trying some new powders this year, and I am especially interested in the +30dF to -30dF window. I would prefer to generate data that other shooters can easily duplicate and share, that we can all more or less take seriously.
Question 1: How long should an ammunition sample sit in a truckbed tool box or the trunk of a car outdoors before it is considered cold soaked, cold all the way through, cooled to ambient temperature?
I think twelve hours is plenty, eight hours maybe, four hours maybe/maybe not, but I don't have a way to measure. What do you think?
Question 2: How long does a firearm need to sit in a truckbed toolbox or car trunk before it can be considered cold all the way through? What if the rifle is zipped into a soft case with a layer of soft foam around it to insulate it? Or a hardcase with foam block cutouts?
I suggest 8 hours ought to be plenty for an unloaded revolver in a leather holster with just enough shop toweling wrapped around it to keep the gun from getting banged up. I will leave the shop towel in the tool box all winter so it only has to cool off the one time.
I have no idea what to propose for a cased rifle, I just though of it just now.
My best plan so far is to shoot one cylinderful of cold soaked ammunition from the cold gun, and then promptly while the gun is still warm a second cylinder of the same load, but the second cylinder of ammunition still warm from the house in the cab of the truck, looking for differences in perceived recoil and group size, ass/u/me-ing I get consistent ignition.
Then I'll have to wait however many hours for the gun to cool off before I can collect another data point.
Going up against H-110 at +15dF in the first round is going to be HS-6.