Powder vs Temperature

[royinidaho]

Am shooting 270 Win and 338 Win will be moving up to 338 RUM........

I work up loads in the summer. Loose more than 100 fps in the winter using RL 22. Havent checked the 338 but suspect similar drops as am using RL powder.

The difference between summer and winter temps can be as much as 80 degrees. Squat, I've seen 50 degree temp changes in the same day.

What cha'll do, huh?

[bigbrother]

Roy,
I've actually worked all my loads in the winter/spring. Try to do them all between 30 and 40 degrees. That's typically the temp that we're doing our long range hunting at. I run all my drop charts at those velocities and temps. In the summer, I always shoot over a groundhog on the first shot using my drop chart. Increase in velocity. But, I always shoot it first, determine how much to take off and kill it with the second. (in theory, sometimes it's the 3rd or 4th) How far over I shoot varies from a 70deg day to a 90deg day. Even though the powder isn't supposed to be that sensitive to temp.

Other shooters I know put their loaded rounds in a cooler to keep the rounds at a constant known temp. (Seems kind of a pain in the to me)

Some guys, shooting the big guns with 114g of powder or so, just take off a couple in the summer and shoot 111 or 112.

Isn't this fun?