poppy, I'm recoil sensitive too. My all time favorite 1oz load is STS hull, STS209 primer, 17gr e3, TGT-12 wad and 1oz hard shot. It is very consistent and I have no problems in cold weather. A couple of weeks ago I shot when it was 11 degrees. My shells sounded fine and smoked targets, while other shooter's shells were blooping. I don't have any problem with using Fed 209A primers in winter, but I only have recipes for the load I gave you using STS209 and W209 primers. Since I don't have a problem with the STS209, I don't see where a hotter primer is needed.
I also like the same components with 18gr of American Select. That is also a soft, really nice load.
What Hull, What Wad? How Cold? Auto, Pump, or Hinge gun?
Use a good powder, decent primer, decent wad, reliable data, and a good scale.
E3, Promo, Red Dot, Clays, Clay Dot and 700-X are among my favorites for light to moderate 1 oz loads. Green Dot will work if you don't load it too light and use a hot primer. I like the Remington STS or AA Hulls and will use either the Winchester WAA12SL or Remington TGT12 wads, or a decent clone like the Downrange versions. The primers I prefer would be the Winchester 209 or the Federal 209A for colder weather. I seem to get better consistency from them in colder weather as a general rule. Go to the powder manufacturer's site for data for the EXACT components that you are using. Loading a slow powder in light charges in colder weather is not a good way to get started. Try to get the pressure in the 9000-9500 psi range if you can. Too low might be troublesome.
Don't load a lot of them the first time. Load a box and put some of them in the freezer for a day before testing them. Shoot them over a chronograph if you have one available to get an idea of what you are getting. You can buy a simple chronograph for under $100. I have an F1 Chrony that works like a charm. It's more consistent with shotshells than one I paid a lot more for. Use the diffusers and if you have interchangeable chokes, use a more open choke to get a more realistic idea of your velocity. I found that tight chokes seem to give a higher reading than an open one does. You can do the testing side by side with some assorted factory ammo to get an idea of what your loads are doing in comparison. The freezer test is sometimes an eye opener.
When it is really cold out I like 2.7 grains of bullseye and a 148 grain hollow base wadcutter. Turn on the heat at the club's outdoor pistol range and I'm good to go. Each firing point has blown hot air coming down from above. HMB
Are the Federal Primers really hotter???? - Recently I loaded 1 1/8 #7 1/2 shot into AA hull - Winchester wad - 19 grains of Green Dot - Win 209 and then the identical stuff except change to a Fed primer ------ went to the range in 30 degree weather. The Winchester primer loads sounded stronger - less powder residue in barrel and better breaks than the Federal primer ------- I was told the Federal primer was hotter and better in winter. I did not shoot either over a chronograpg but reaction of the target was infavor of the Wincheter primer -----in this one non replicated test.
I shoot winchester primers and 700x all year round. I shoot weekly throughout the winter in Wisconsin. From 40 to -10 degrees and I have never had any problem shells. Except for one time when I forgot to add powder...another story...