Thread: Is 2225 very temp sensitive?

Originally Posted by 338

If all goes to plan I will have answers by tomorrow night.

I would be keen on hearing results on taking temperarure of cases in various situations but then pulling the projectile and taking temperature of powder as well. Im curious about how much the temp of the powder itself changes. From that you could then work out a formula for powder temp.based on case temp and have something more definitive. All chronyed through cold barrel of course to keep things equal. Dont want barrel/chamber temp and associated effects swaying things

Originally Posted by horihunter

I would be keen on hearing results on taking temperarure of cases in various situations but then pulling the projectile and taking temperature of powder as well. Im curious about how much the temp of the powder itself changes. From that you could then work out a formula for powder temp.based on case temp and have something more definitive. All chronyed through cold barrel of course to keep things equal. Dont want barrel/chamber temp and associated effects swaying things

You dont want much

Originally Posted by 7mmsaum

You dont want much

Not a fan of subjective conclusions

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"