Humidity affecting pattern?

[kevind]

Shot today with following conditions....71 degrees...86% humidity....how much would the humidity affect numbers?  Shot 337+- in a 10 inch at 40 yards with jelly head .670...shooting Hals 18 g/cc 9 loads in 2.25 oz and my buddy threw 427 through a Rhino .670 with 38% humidity...he is shooting a 26 and I a 28 ...both invector plus barrels.  Would the weather affect it that much or is it the difference in choke or the 2 inches of barrel difference...both clean barrels...thanks for the help!

[kevind]

Would the humidity throw it off 50?

[allaboutshooting]

All of the above.

I'd have to agree with that. While chokes and barrels may seem similar they can be quite different. When you throw in different barrel lengths and atmospheric conditions, there are just too many variables to compare.

Barometric pressure and temperature effect patterns more than relative humidity as well.

In theory, higher relative humidity would produce less air density but we've just not seen that in practice at still target shoots or it could be that other conditions have influenced the shot more than humidity in the air. Records have generally been set when it was hot and dry.

Thanks,
Clark

[kevind]

Thanks guys for the help!

[allaboutshooting]

All of the above.

I'd have to agree with that. While chokes and barrels may seem similar they can be quite different. When you throw in different barrel lengths and atmospheric conditions, there are just too many variables to compare.

Barometric pressure and temperature effect patterns more than relative humidity as well.

In theory, higher relative humidity would produce less air density but we've just not seen that in practice at still target shoots or it cold be that other conditions have influenced the shot more than humidity in the air. Records have generally been set when it was hot and dry.

Thanks,
Clark

Agreed, but not just in theory. It is a fact that increased relative humidity makes the air less dense. And in theory, anything that makes the air less dense, should improve (i.e. tighten) patterns. I also agree that the effect is less important than the temperature effect.

I stand corrected. I formed my sentences incorrectly. You are of course correct. It is not theory that increased relative humidity makes air less dense, it is as you said, theory that it would improve patterns.

It's one of those things that many of us have discussed over the years. I even wrote an article about that subject in which I interviewed several shotshell manufacturers and asked them their "boots on the ground" experiences, to determine if theirs were the same as mine. They were. All saw much better, more dense, patterns when the air was drier.

For anyone interested, here's a link to that article http://allaboutshooting.com/article_info.php?articles_id=381

Thanks,
Clark