Loading for changing temps

[Eoddave27]

Hey guys. I have have only been reloading for rifle since the spring. I’ve picked up a ton of info here and have pretty accurate loads for all my rifles. My question is about summer and winter shooting. I have a great RL17 load for my 6.5 creedmoor that consistently shoots sub .5 MOA. However now that the temps have dropped it shoots like crap. My question is do you guys have a summer and a winter load or you just try to get a temperature stable powder and use the same load year around? Right now I’m kind of starting all over with my 6.5. I have finally been able to find some H4350 so I’m going to try that as it seems like all my Varget loads still seem to shoot about the same. I don’t think I’m going to be able to get the velocity that I have been able to get out of the RL17 but if the trade off is consistency it may be worth it.

 

[honuswagner]

Where I'm at it's not uncommon to have 30-40° temp swings from morning to afternoon, highs in the 90s in summer, single digits in the winter. Powder temp sensitivity has always been a deciding factor.

I've found the Hodgdon Extreme line to be inensitive to temp swings. A few weeks ago I was clocking rounds throughout the day, H4350. The same loads averaged 7 fps faster at 65° than they did at 44°, 0.2% sensitivity factor based on that. I don't consider that an extreme temperature range, but that's the data I have at the moment. I'll gather more data as it gets colder.

I bought into Hodgdon marketing hype, and considered feedback from other shooters, and went with H powders first for my 6.5 CM, so I admit I haven't compared H2H with other brands.