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FrankenMauser · September 11, 2012, 07:01 PM

Never rule out shooter error. But...

It's quite possible that the Varget was showing some temperature sensitivity.
The best load my .270 Win has ever seen was something like 52 gr RamShot Hunter, under a 140 gr Partition. It provided the proverbial "one-hole groups".
But... it would only do that around 40-50 degrees F. Once the temperature came up to even the mid-60s, the groups opened.

And... don't buy manufacturer's claims of powders not being temperature sensitive. I've seen the same sensitivity with some of Hodgdon's "Extreme" powders.

Yet... one of the most temperature insensitive powders I've encountered is RL-19. ....something that most reloaders, ballisticians, and gun writers constantly flaunt as very temperature sensitive, due to its "primitive" double-base chemistry and extruded shape.

Just like charge weights and accuracy... you never know how a powder will react at any given temperature, until you try it. (Getting data for RL-19's temperature tolerance took me nearly 2 years, because I had to wait on the weather. (I tested a few others, as well.))

September 11, 2012, 07:01 PM	#14
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	Never rule out shooter error. But... It's quite possible that the Varget was showing some temperature sensitivity. The best load my .270 Win has ever seen was something like 52 gr RamShot Hunter, under a 140 gr Partition. It provided the proverbial "one-hole groups". But... it would only do that around 40-50 degrees F. Once the temperature came up to even the mid-60s, the groups opened. And... don't buy manufacturer's claims of powders not being temperature sensitive. I've seen the same sensitivity with some of Hodgdon's "Extreme" powders. Yet... one of the most temperature insensitive powders I've encountered is RL-19. ....something that most reloaders, ballisticians, and gun writers constantly flaunt as very temperature sensitive, due to its "primitive" double-base chemistry and extruded shape. Just like charge weights and accuracy... you never know how a powder will react at any given temperature, until you try it. (Getting data for RL-19's temperature tolerance took me nearly 2 years, because I had to wait on the weather. (I tested a few others, as well.)) __________________ Don't even try it. It's even worse than the internet would lead you to believe.