IMR 4064

**Krazykarl** · 01-13-22, 17:45

What is the ambient temperature effect on IMR 4064? Can't find much doing online searches...

**gunnerblue** · 01-13-22, 18:21

Are you asking if it's sensitive to temperature changes regarding velocity and/or pressure? I've used it for awhile in .300 Savage and it handled temp changes well between shooting in the hot (+90) summer and hunting in the fall and winter when temps will drop below freezing. I’ve always liked 4064 in the so-called medium calibers like the Savage and .308.

**Krazykarl** · 01-13-22, 18:32

Yes, I want to know if IMR 4064 will be temperature sensitive in regards to pressure and velocity variation. For example, I just worked up a very nice load for 6.5 creed using 123 gr bullet and IMR 4064. Here in the great lakes region, it was 10 above when tested. During the summer pronghorn season, will there be issues? Of course further testing will bear this out..

**archad** · 01-13-22, 18:59

Can you PM your load data?

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**Krazykarl** · 01-13-22, 19:06

I can provide results tomorrow. Thanks guys!

**markm** · 01-13-22, 22:11

IMR 4064 is pretty temp stable. That's something it's known for. There was gobs of info on it compared to Reloader powder with relation to the Military Long Range 762 load development.

For whatever reason, the MLR18 (or whatever the designation) still used Reloader even though IMR 4064 was MASSIVELY more temp stable. Not even close!!

I've ran a few different lots of IMR 4064, and have had pretty big velocity swings due to lot change.... I'm talking over 100 fps in .308. I like the powder, but you need to work it lot by lot.

**Krazykarl** · 01-14-22, 07:19

IMR 4064 has been a constant companion in my family with great results. The only negative experience was 6.5 Swede in the m96. IMR 4064 was too fast for the 29 inch barrel producing a smoking action and carbon streaking on the brass. I switched to IMR 4350 and got better results and the pressure stayed high enough and long enough for the bullet to leave the barrel AND keep the brass sealed against the chamber walls. I am home now and will provide my results of the 6.5 Creedmore..