Hot barrel, cold barrel

[upacreek]

What is your rule of thumb for accurate barrel temp? What is too hot?

 

[J E Custom]

What is your rule of thumb for accurate barrel temp? What is too hot?

If you can't hold the back of your hand on the barrel indefinitely, you should slow down or give it a rest.

On the big Magnums 2 or 3 shots in quick succession will do it.

A barrel can get hotter and still be accurate but barrel life will be shortened when the barrel heats up past this point and firing continues.

J E CUSTOM

 

[upacreek]

Thanks for the reply. That is the rule of thumb I have always lived by, just wanted to verify it. What about first shot cold? Hunting can be mid teens. First shot warms the barrel to sub 100deg temps, but how do you throw one round to get the barrel warm? Has anyone lost accuracy in sub-freezing temps?

 

[cdherman]

Thanks for the reply. That is the rule of thumb I have always lived by, just wanted to verify it. What about first shot cold? Hunting can be mid teens. First shot warms the barrel to sub 100deg temps, but how do you throw one round to get the barrel warm? Has anyone lost accuracy in sub-freezing temps?

Most certainly you can, and almost always do lose some accuracy in very low temps. And guns, loads, powder and probably even bullets vary in terms of the degree of that effect.

I am old to hunting but really a neophyte to the long range stuff. If I were on a once in a lifetime hunt, where very low temps were expected, I would find some way to test my loads ahead of time. Both in terms of group size accuracy, but also first shot zero accuracy.

Won't do you any good at all to have a 0.25" group with a warm barrel at 68deg, only to have the first shot at 10deg be 3 MOA wide....

I think first shot from cold barrel accuracy is not discussed enough in hunting arms. We go to the range and fire a fouler -- that always warms the barrel considerably. I often shoot two foulers. And then proceed to shoot some groups.

I am always careful to make sure that a fouler has been fired in a hunting rifle before I set out for real, but barrel temp is harder to control for.

The good news is that steel does not behave that much different at 10 degrees versus 40 degrees. So you can get a certain level of assurance by at least firing a cold barrel accuracy test at some more common temp (say 40) in the fall.

I have mused (and intend to do so for this year, as Kansas is waaayyy late) that a good "acid test" would be to fire my final warm barrel test group, to verify load and POI. And then let the gun fully cool. Either come back a different day, or wait a good hour or two (you can save the target and shoot some other guns).

Then fire the last round from the cold barrel into the original group. If its in the group, you are pretty good to go, I would think....

 

[justgoto]

I develop loads during winter for winter.

 

[Mikecr]

+1 justgoto
I develop for the temp range intended.
The ONLY shot that matters is the first.

While hunting, after laser ranging & dialing, I pull a round from my front pants pocket and load it single shot with the barrel pointed upward, and then carefully set the bipod in the dirt, & check my level, just prior to killing something. When I develop cold-bore loads, this is just what I do for every shot.