Thread: Is 2225 very temp sensitive?

Today I loaded up 6 rounds consisting of 93grains of 2225, remington brass, federal magnum match primer and a berger otm 300gr for my edge.
3 rounds I sealed up and sat on ice for half a hour (colder than they would ever get in hawkesbay) and the other 3 I put in my pocket with the snap disk type hand warmers (hotter than what the Hawkesbay summers would be able to get them)

The barrel was left to cool after each shot.

The results were very interesting!

COLD loads measured 2803, 2785, 2770

HOT loads measured 2748, 2744, 2750

I was almost doubting my chrony because I had always thought the hotter the powder the higher the pressures? But this data was backed up by both the impact point at 340yards being 1.5" different between groups and the obvious pressure signs on the cold cases!

A outcome I was not expecting but I was still pleased to see that if I set my velocity for my balistics chart to 2767 fps that will give me 20 fps variation either way at the VERY most which is only going to throw me 4" at 1000yards but even then if I keep the bullets in my pocket when I hunt and sight in etc it will close it down to more like 2" due to the reasonably constant temp of a pocket.

I will add that both groups at 340yards were well under 2"