Bullet trajectory and weather?

H

hawk-i

CGN Ultra frequent flyer
Rating - 100%
9   0   0
So the question is, does heavy rain or snow affect trajectory of a bullet in flight?

Was out yesterday in heavy snow (rabbit skins), could barely make out the target at 810 yards (4'x4' plywood with 3" black dot) but wanted to confirm drop anyways. (new rifle and scope)

6.5 PRC 143 ELD-X factory ammo (Fierce Carbon edge), Zeiss V-4 6-24x50 ZMOAi-20 #89.

Zero @ 100yards, 17.25 MOA up. (From Zero scope still has 69 MOA up available)

3 shot group @ just over 5" --wasn't sure if I could even hit the target with it snowing like it was.

Other than visibility, does heavy weather make a difference?
 
Last edited:
Even in heavy rain we can usually see quite far, so there can't be all that much water in the air at any given moment.

At first glance it would make sense that a bullet hitting a rain drop would have some affect on point of impact, but from what I've read it does not seem to be the case and precipitation has a negligible effect on trajectory or accuracy.

I wonder if the rain was heavy enough if that would still be the case though. Perhaps there may be a correlation to how far you could see during the rain, meaning how far you can see would indicate how much water the bullet might contend with while in flight. But, that would mean you could not see the target you are shooting at and that makes the question purely theoretical.

So maybe that's the answer... If you can see the target, the water in the air is of negligible effect.
 
Last edited:
I've been researching this on the inter-webs and it looks like shooting on rainy days will most likely cause your bullet to hit slightly higher than normal.

One site said your BC of the bullet will increase roughly 3% on rainy days.

Another site suggests it's not the rain but that rainy days occur on low pressure days so less dense atmosphere compared to sunny high pressure days...this make the most sense to me.

Probably the guys that do a lot of competitive shooting can confirm this?
 
Rain in the air only affects your bullet in that higher humidity actually causes the air's density to be less, ergo hitting higher in the rain. If you're using something like a Kestrel to get the atmospheric conditions at your shooting location then your dope should be one for those conditions. That's obviously not taking into account your ability to see (or not) the target.
 
Boon20 said:
The bullet is moving so fast it creates friction witch creats heat and it burns the moisture out of the way. Thats why in high humid enviroments there is a vapor trail that spotters use to track the bullet.

Snow and rain doesnt affect the trajectory. Temp on the other hand does just remember cold air is heavy(add mil/ moa) worm air is light(subract mil/moa).

If you are using a hunting bullet like a ballistic tip the bullet could be coming apart at extended ranges so it is important to figure out where that point is if you are.
Click to expand...

Not even close. The bullet is heated by friction in the barrel, not the air. It doesn't evaporate moisture in the air.
Much more likely cause of bullet trace is the localized area of low air pressure directly behind the bullet. This low pressure causes the air temperature to drop, and moisture condenses out of the air.
https://en.wikipedia.org/wiki/Vapor_cone

Higher humidity means the air is thinner, meaning less drop not more. And not much less, humidity is one of the least impactful atmospheric factors. Also, humidity doesn't normally change just by itself, the air pressure and temperature all combine to affect the trajectory.
 
You must log in or register to reply here.
Back
Top Bottom