Thread: Random pressure signs?

Originally Posted by 338

I get this all the time in the cold. When I am hunting in the snow some of my loads stamp like a bitch! Keep them in your pocket.
I have actually tested this a few years ago with 2225 and 2217 powder using ice packs and hand warmers to heat and cool rounds.
Shot at 400 and had higher velocity’s,higher point of impact and pressure signs on the brass on the cold rounds


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Interesting. Cold shrinks metal. The relative differences in coefficients of expansion of the several metal involved, e.g. barrel, brass, bullet would change things like neck tension and case capacity, even headspace. Loaded close to limits, these combined factors may have a more noticeable cumulative effect than with a more mild load.

Originally Posted by Woody

Interesting. Cold shrinks metal. The relative differences in coefficients of expansion of the several metal involved, e.g. barrel, brass, bullet would change things like neck tension and case capacity, even headspace. Loaded close to limits, these combined factors may have a more noticeable cumulative effect than with a more mild load.

Had the same thought, will be interesting to try putting the remaining rounds thru when its a bit warmer and see if there is an issue.

I the mean time would folks keep using the load? slightly heavy bolt lift and light extractor mark. Or do I need to look for a different winter loading (would be a ball ache!)