Ammunition Speed vs Weather

[JimReed1948]

I'm very new to rimfire benchrest and here's my latest question.

Is there a rule of thumb for the ammunition speed to use during certain weather conditions?

What ammunition speed works better in cold conditions?

What ammunition speed works better in hot & humid conditions?

 

[blades]

A better way to look at this is : What ammo does your rifle like in these conditions, and as each rifle has its own preferences there is no definite answer. That said most rimfire ammo will show a lower velocity in cold conditions say 40 deg. vs say a median of 75 deg. and most will show a velocity increase when it is fairly hot out. So to counter act this one could use a faster velocity in the cold and slower in the hot and at the same time trying to stay in the sweet spot of the rifle.
Clear as mud, hope it is of some help.

 

[JimReed1948]

A better way to look at this is : What ammo does your rifle like in these conditions, and as each rifle has its own preferences there is no definite answer. That said most rimfire ammo will show a lower velocity in cold conditions say 40 deg. vs say a median of 75 deg. and most will show a velocity increase when it is fairly hot out. So to counter act this one could use a faster velocity in the cold and slower in the hot and at the same time trying to stay in the sweet spot of the rifle.
Clear as mud, hope it is of some help.

Yeah. That makes since. I was at a match not too long ago and the guy next to me was telling me how high the humidity was. He had been shooting ammo around the 1062 area and dropped down to a slower speed. This goes along with what you're saying. I never thought about it like that until I read your post.

Thanks