codyadams
Well-Known Member
So I did a temperature test, I'll go over how I conducted it. I put 5 rounds in a zip lock bag in my freezer overnight, then on my way to the range I put the rounds in a bucket filled with ice, and put my kestrel inside so I had a temperature I could monitor and record. The other rounds were kept at room temperature in my house, then on my dashboard in my truck on the way to the range.
When I got to the range and set up my chronograph, I got my bucket of ice and pulled my kestrel out and looked at the temp, it registered 17° f, but by the time I thought to get my phone out and take a picture, it had warmed up to the 30's, as the ambient temp outside was in the high 60's. After this I put my kestrel in my ammo box with my room temp rounds.
First I shot the chilled rounds, pulling them out of the ice one at a time, and I shot them within about 3 seconds of chambering them, and recording velocity. Then after that, I let my barrel cool to room temp, then looked at the temp in my ammo box, which was 67 ° f. Then I shot those 5 rounds, and recorded velocity.
This was my load for all rounds fired in my .260 AI:
49.1 grains RL-26
Lapua Brass
CCI BR-2 primer
140 Berger VLD Seated .005 off lands
And these were my velocity results:
17° f -
1. 3051
2. 3046
3. 3056
4. 3066
5. 3055 AVG. 3054, E.S. 20 FPS
67° f -
1. 3060
2. 3059
3. 3055
4. 3058
5. 3063 AVG. 3059, E.S. 8 FPS
My lower temp loads would have had a 10 fps e.s. If it wasn't for the one that went 3066, and also would have averaged 3052 instead of 3054. But even at that...The velocity spread for 50° f difference was only 7 fps...so all my worries about temp sensativity are now dismissed, at least for this rifle.
When I got to the range and set up my chronograph, I got my bucket of ice and pulled my kestrel out and looked at the temp, it registered 17° f, but by the time I thought to get my phone out and take a picture, it had warmed up to the 30's, as the ambient temp outside was in the high 60's. After this I put my kestrel in my ammo box with my room temp rounds.
First I shot the chilled rounds, pulling them out of the ice one at a time, and I shot them within about 3 seconds of chambering them, and recording velocity. Then after that, I let my barrel cool to room temp, then looked at the temp in my ammo box, which was 67 ° f. Then I shot those 5 rounds, and recorded velocity.
This was my load for all rounds fired in my .260 AI:
49.1 grains RL-26
Lapua Brass
CCI BR-2 primer
140 Berger VLD Seated .005 off lands
And these were my velocity results:
17° f -
1. 3051
2. 3046
3. 3056
4. 3066
5. 3055 AVG. 3054, E.S. 20 FPS
67° f -
1. 3060
2. 3059
3. 3055
4. 3058
5. 3063 AVG. 3059, E.S. 8 FPS
My lower temp loads would have had a 10 fps e.s. If it wasn't for the one that went 3066, and also would have averaged 3052 instead of 3054. But even at that...The velocity spread for 50° f difference was only 7 fps...so all my worries about temp sensativity are now dismissed, at least for this rifle.
