Cold Weather Reduces Shotgun Range
Cold weather reduces pattern density and therefore your maximum range. Keep this in mind when you are patterning your shotgun during the summer for a fall hunt.
Below is an example of what you might see in a 40-yard, 300-pellet, 10-inch pattern shot at different temperatures. This would be for H-13 7’s or Hevi-Shot 7.5’s. Be sure to shoot your gun in both cold and warm temperatures so you can make proper shot selections based on the conditions.
Temperature________10” Pattern (3-Shot Average)
If your rig does better than this, great! But you can see why many turkey hunters would max out at around 280 when they pattern in the spring.
Make sure you shoot multiple shots at different temps. Your pattern variation may be great enough that you see some overlap between temps that are 10 or more degrees apart. You will start to see a temperature related pattern differences through repeated shooting and taking the average counts.
Right now you will get some of the best patterns your choke can produce. Get out, shoot a few, and start counting!