loading for the temperature

[jmason]

If you find a load your gun shoots well, and it's warmer than it will be in hunting season would you use a powder charge that's at the high end of the node in anticiption of cooler temps?

[Boss Hoss]

Depending on the rifle and powder I do it all of the time BUT the chrono is the way you can tell what is really going on. There is no free lunch so to speak. Never have I had a load that shot at a higher velocity on a colder day.

A possible issue is the 1st shot thru a clean tube--higher pressure possibly and with factory tubes most likely a different POI. Just something to keep in mind..

[royinidaho]

RL-22 in 270 Win. - 130 FPS velocity reduction from 70* summer temp to teens in winter.

With powders such as IMR 7828ssc I load to max in less than 70* temps and don't worry about it except in my long range guns where I am a bit more particular.

When I chrono a given load @ lower temperatures it is always lower than in warmer temps. If it is sufficiently low I enter the lower velocity into the drop chart program and make a new drop chart. I'm not one to have a cold weather load and a warm weather load. I'd invariably get'em mixed up sooner or later.

[papa45]

Ditto.

Another thought... Reduced velocity at lower temperatures can change more than just trajectory. Barrel harmonics can affect group size and POI. jmason's idea of using a charge that's at the high end of the node sounds like a reasonable approach, but the only way to tell for sure is to test at the anticipated lower temperatures.

[jmason]

Originally Posted by papa45

Ditto.

Another thought... Reduced velocity at lower temperatures can change more than just trajectory. Barrel harmonics can affect group size and POI. jmason's idea of using a charge that's at the high end of the node sounds like a reasonable approach, but the only way to tell for sure is to test at the anticipated lower temperatures.

Thanks guys. I will test it in colder weather for sure. I was just looking for validation of my thought.

[AJ Peacock]

Originally Posted by jmason

If you find a load your gun shoots well, and it's warmer than it will be in hunting season would you use a powder charge that's at the high end of the node in anticiption of cooler temps?

Thats exactly what I do. I figure the lower temps will still keep it in the node.

AJ

[royinidaho]

I figure that if group size doesn't change with large drops in temperature with 200 yd point of impact being the only change, a tweak up in zero setting being necessary, then the drop chart change is considered based on a downrange point of impact check along with the chrono check.

There was a thread a while ago, regarding "how wide is your node". That consideration is very important. Node width seems begs for a bit more consideration of the OCW method of load development along with the Ladder method.