What effect does humidity have on accuracy?

[dutch14]

It is hard to hold study on target when you are shivering.

 

[Unclered]

The biggest issue with cold temps and or humidity is ignition. Rimfire powders are slow burning and dirty. Almost as bad as black powder. When you consider there is only a grain or slightly more, the burn is very critical. A 30 or 40 FPS difference is HUGE when you only strolling along at 1080. % wise it is dramatically more than a 3000 FPS pill. I’ve shot the same ammo cold vs warm. (I’ve also shot black powder at 10 degrees) center fires with today’s powders are not as temperamental.

 

[Todd Earhart]

A 6 card night tournament at buckcreek gives a person the effect of it. Match starts at 6pm and usually ends right after midnight. Clear with wind, water vapor, fog and possibly a 30 degree temperature swing. By the last cards you better be sure your aiming at what you think you are.
Todd

 

[gunsandgunsmithing]

A 6 card night tournament at buckcreek gives a person the effect of it. Match starts at 6pm and usually ends right after midnight. Clear with wind, water vapor, fog and possibly a 30 degree temperature swing. By the last cards you better be sure your aiming at what you think you are.
Todd

Love that place and Jackie and all the regulars. It can be tough and it has very good moments, too. Been a while since we had a cf night shoot there. Might try to talk Jackie into doing one this year, if he's up for it. Led's have made it a lot more plausible than it used to be.

 

[Dolomite]

Aside from the wind or visibility issues how do you compensate for lower to higher humidity? Adjust seating depth or powder? For powder do you add more or less to your standard load when humidity increases or decreases?

 

[grauhanen]

Aside from the wind or visibility issues how do you compensate for lower to higher humidity? Adjust seating depth or powder? For powder do you add more or less to your standard load when humidity increases or decreases?

This is rimfire.

 

[Bill Norris]

Aside from the wind or visibility issues how do you compensate for lower to higher humidity? Adjust seating depth or powder? For powder do you add more or less to your standard load when humidity increases or decreases?

Bench Rest shooters add more powder normally when the day wears on and humidity begins to burn off according to Jack Neary.

 

[gunsandgunsmithing]

What do the groups yell you to do? There's a leaning curve to doing this game well and no shortcut because there are so many variables, like case capacity, powder used, a tuner... and the gun itself.

 

[Dolomite]

This is rimfire.

Please accept my apologies for my post about CF. I should have read the OP.

 

[gunsandgunsmithing]

Please accept my apologies for my post about CF. I should have read the OP.

Me too but same, same.

 

[Dolomite]

 

[mikecr]

For the piston-bullet pushing different air density slugs out the barrel, and constrained to rimfire, I would think a barrel tuner could restore results. It's point blank range, so BC change could be practically dismissed.

 

[Topstrap]

Running my rimfire matches I've seen some strange things happen. I know the abilities of most of my regular shooters. Certain days nearly everyone of them will comment they have had to use less elevation working their way out thru the racks and all will be using nearly the same difference in their settings. As the day progresses settings will slowly start to come back in line.

I don't check weather settings but this wasn't a temperature issue but appeared to be humidity/air density issue. When you see this happening to upper level competitors using top equipment/ammo there is something going on. Nearly impossible to see there will be a difference before you start but if target hits tell you something is going on pay attention and listen to what the impacts are telling you.

After the match compare notes and maybe draw a conclusion.

Topstrap

 

[6Creed73]

With humidity comes mirage and the target dances. It is hard to find a consistent firing point hence poorer accuracy. Happens to me with centerfire guns at long ranges like 1000 yards.

David

My experience is the complete opposite. Dry hot days make for bad mirage, think about the desert. When humidity rises, the mirage goes away.

With that said, humidity can bring other visibility issues. Vapor increases with higher humidity, which can cause fog and hazy conditions. But I'd rather shoot in haze than mirage, as long as I can still see the target.

 

[CNC-Dude]

If humidity negatively affects accuracy, it must cause all rounds to somehow fly less accurately to the target. The alternative is that humidity affects only some rounds in a box, but not all.

Is there reliable, quality evidence about the relationship between higher or lower humidity levels on ammo performance?

Watch the Brian Litz and Erik Cortina podcast mentioned above, Brian covers that very topic in it....

 

[grauhanen]

Watch the Brian Litz and Erik Cortina podcast mentioned above, Brian covers that very topic in it....

A hint at what they say about .22LR performance and humidity might be useful.

 

[dstoenner]

My experience is the complete opposite. Dry hot days make for bad mirage, think about the desert. When humidity rises, the mirage goes away.

With that said, humidity can bring other visibility issues. Vapor increases with higher humidity, which can cause fog and hazy conditions. But I'd rather shoot in haze than mirage, as long as I can still see the target.

Maybe humidity is different in the desert areas, i can’t say but where i live in North Carolina it is like soup. I remember one match in April, it started out muggy and by 10 for the last match we just dripped. This is a 100 yard rimfire match. That bull would just dance around as a breeze would pick up. I lost 4 points on that bull. Never did see the rings of the target and just shot center mass and hoped. Other days it is lower humidity and there is no to low mirage and it is not an issue.

Just my own experience.

 

[Liven The Dream]

To add to this post.
Took my CZ 457 to the Range two days ago. It was 43 degrees little over cast.
The Rifle and Ammo had a nice warm ride to the Range. This Rifle has a Lilja Barrel Bedded.
I have shot nice groups at 50 &100 yards.
I just install a Jard Trigger.
I fired a few shot to re zero the Scope.
Based on other posts ! .22 Rim Fire Ammo and Rifle perform poorer in cold Weather ?

I shot some of the best groups with this Rifle. The most puzzling to me was Ely Black Box ?
In the past it shot good not great SK std. was better. This time at 50 yards 5 shots under a button size group.

The Weather, New Trigger,my day or a fluke day at the Range ? I came Home Happy.

 

[MUP]

What size button?

 

[BowChamp]

What size button?

I'm a button shooter myself.........That'll be close enough!! LOL!!!