Temperature effect on Velocity

[Palladin]

Looking for some information on the effects of temperature on velocity. Tested some 223 75AMax loads at 4-5C and averaged 2906fps on what looked like the right load......went back out to retest at 22C and averaged 2977fps....I'm getting flyers at the higher velocity. Any advice is appreciated.

 

[furet]

Colder air is denser so more resistance, I don't know if that would have an impact on velocity so close to the muzzle. But was your barrel that cold, cus barrel temperature will have an impact on velocity.

 

[Palladin]

I fire a few rounds thru the barrel before chrony to heat it up..........

 

[bnichols]

Burn rate for some powders is more affected by temperature than others. What powder were you using?

 

[ricciardelli]

http://stevespages.com/tempvsvelocity.html

 

[Palladin]

Thanks for the chart....its in line with what I found with my testing.

 

[mikeelliot]

Try a Hogdon Extreme powder, IE Varget.