Rimfire Ammo Temperature

[doghunter]

Here in my part of Oz it's currently 0°C (32°F) so pretty cool.

I have noticed that my ancient Annie 1411 Match 54 does not perform as well with Eley Tenex at below 10°C as it does when warmer days happen.

I have resorted to keeping my Tenex ammo under my armpit or using Lapua Polar Biathlon which is designed for the cold but not as quite precise.

So why don't rimfire ammo like cold days and why?

* doggie *

 

[vtmarmot]

I can't say for sure, but it is a well-known phenomenon that probably has something to do with the powder lacking the chemistry for temperature-insensitivity.

If the temperature is below 50 degrees farenheit or so, I keep my rimfire ammo in an insulated lunch cooler with one of those had-warmer packets that you shake to activate.

 

[tim]

RF match ammo does not perform best under about 50 deg mostly because allthat great bullet lube you paid for does not distribute well down the bore when everything is cold.