Shooting in the rain, Point of impact

[bdub]

How does your point of impact change when shooting in the rain? Just wondering if anybody knows offhand? I remember reading something on it a while back but I can't remember the conclusion was. Thanks

[lone wolf]

Originally Posted by bdub

How does your point of impact change when shooting in the rain? Just wondering if anybody knows offhand? I remember reading something on it a while back but I can't remember the conclusion was. Thanks

I have heard that with (major) changes in relative humidity, wood stocks can swell or contract, and effectively change point of impact. Looking forward to hearing some of the other swearer and experiences of fellow shooters.

[bdub]

Originally Posted by lone wolf

I have heard that with (major) changes in relative humidity, wood stocks can swell or contract, and effectively change point of impact. Looking forward to hearing some of the other swearer and experiences of fellow shooters.

Yes you bet. I was more wondering how it affected the bullet in flight. It seems to me that groups would be larger but not sure and if so how much at various ranges.

[375FMNE]

I was told about 25 years ago by an international competitor that point of impact was higher in the rain. Never tried to figure it out for myself. 375

[elkhunter11]

I never noticed any change in point of impact, or in group size, when shooting in the rain.

[tchardy1972]

At distance iv noticed most competitors shoot better in the rain at distance. I think it is easier to call condition changes. Personally though, I get upset about my gear being wet and fall apart.

[roger]

anyone ever notice a when a shot is videoed and watched in slo-mo that the rain pattern is disrupted for a second?
could it be the pressure waves in front of the bullet clears a path by deflecting waterdrops, i dunno. like a boat cuts through water,?? so it makes me wonder if rain is even an issue, because its really no different than ordinary humidity on an ordinary day, just the droplets are bigger.
interesting..

[bigshell]

I've shot my best groups in rain,but that could be a fluke too.

[DaleJ]

At longer ranges point of impact should be slightly higher, as humid air is less dense than dry air, resulting in slightly higher velocity through bullets flight. Other conditions such as visibility and wind will have a greater influence on bullet flight. By longer ranges I mean 500 yards or more.

[Dean2]

Major enviro factors that affect bullet flight in descending order of affect wind speed and direction, air density, temperature, barometric pressure.

At least in Alberta, humid air is usually denser than dry air. Most of the time in the rain, the wind is not blowing very hard and tends to be way less gusty than dry and sunny, and it tends to be quite a bit cooler. Group size wise not much should change, if anything the lower wind factor should help a lot at 200 and beyond. POI shift will very much depend on how much the temp affects the powder you use, the air density will also have an affect. Check drop tables at sea level versus 4000 foot elevation, you can see quite a vertical change. On a 130 grain 308 doing 3150 FPS, at sea level 30.2 low, at 4000 feet only 27.9 low, due to the thinner air.

So all things considered, at 300 yards, groups should be pretty good due to low wind, temp will slow most powders so from a little to some velocity drop, combined with the denser air should mean that generally you POI will be lower than on sunny warm days.

[ehntr]

Originally Posted by Dean2

At least in Alberta, humid air is usually denser than dry air.

Dale has it right Dean...............humid air is less dense than dry air.

[Dean2]

Originally Posted by ehntr

Dale has it right Dean...............humid air is less dense than dry air.

Major Brain fart, you are corrrect, damp air is less dense than dry air.