Look through data to find a recipe that calls for a Federal 209A or a CCI Magnum primer in that order. You might find it to work much better as the primers are designed to be very "hot" and are highly recommend for slow burning powders. I would also look at the published pressures and try those that are as high as possible. I like 10,000 psi at least for cold weather loads.
Other things I have discovered is to use OEM wads rather than clones as the original manufacture tend to remain pliable to lower temps. I also prefer to use Winchester AA or Remington STS hulls as they produce the highest pressures for a given powder charge and the slightly smaller powder charge is somewhat easier to ignite. The various Reifenhauser hulls are the worst as they are very capacious and the hulls are more pliable which might reduce pressures initially. A heavier shot charge also tends to promote proper burning as the greater resistance increases pressures.
You might also want to check your reloader to ensure the wad guide has all its fingers and/or is adjusted properly. If not, the wad skirt can catch on the end of the hull and cause a tear or dent. This can allow gas to escape which is at its worst during cold temperatures. If I feel the slightest hitch when reloading hulls, those shells get tossed into the "summer" bin as I won't trust them when temps get cold - around 20 degrees or less.
