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Poodleshooter · July 26, 2002, 02:08 PM

I see a rough difference of 50-100fps over a 30-40degree temperature change when using 846 versus IMR4064 or 4320 where I really don't find any variation outside of my usual ES. I posted awhile back about some really high velocities obtained on a 100degree day, mostly with AA2520 and WC846 loads that were pretty much the same as factory velocity on milder days. Mostly, its the increased pressure signs that you notice when shooting ball powders on a hot day.
Accuracy doesn't suffer, but if you're thinking about highpower shooting other than reduced course, I'd probably stick to Varget,some VV powder-anything but surplus ball powder. It's great inside 300 yds where you don't have to worry about velocity variations, but past that, if the temperature varies a lot, I could imagine it wouldn't be pretty. (I shoot reduced course, so my knowledge past 300yds is slight).

July 26, 2002, 02:08 PM	#4
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 2,599	I see a rough difference of 50-100fps over a 30-40degree temperature change when using 846 versus IMR4064 or 4320 where I really don't find any variation outside of my usual ES. I posted awhile back about some really high velocities obtained on a 100degree day, mostly with AA2520 and WC846 loads that were pretty much the same as factory velocity on milder days. Mostly, its the increased pressure signs that you notice when shooting ball powders on a hot day. Accuracy doesn't suffer, but if you're thinking about highpower shooting other than reduced course, I'd probably stick to Varget,some VV powder-anything but surplus ball powder. It's great inside 300 yds where you don't have to worry about velocity variations, but past that, if the temperature varies a lot, I could imagine it wouldn't be pretty. (I shoot reduced course, so my knowledge past 300yds is slight).