How does rain effect bullet trajectory?

[Vlad]

I was at a gun shop earlier this week BSing with the proprietor of the store while we were watching the rain come down in buckets. He said that he had done video of handgun shooting in the rain and said it was pretty cool that if you slowed down the tape, you could see the trajectory of the bullet in the rain as it hit and vaporized the drops. This got us to thinking about how does rain effect bullet trajectory at 100, 200, 300+ yards with rifles. Looking at first shot, cold bore. Does the falling rain change the point of impact when compared to the same conditions but no rain? Will the rain hitting the bullet/ bullet hitting the rain drive down the point of impact due to greater resistance?

When you see commercials touting bullets that will expand and explode in a grape, how will that bullet fair in a rain storm, would the bullet come apart when it hits a drop that upsets it?

What do you think? Are there articles to prove or disprove what happens?

[DeanC]

I shoot between the drops.

[Stradawhovious]

The bullet, assuming it's traveling supersonic, has a shockwave that travels before it, above it and to the sides that will more than likely render the effects of the rain inert.

[LarryFlew]

I have shot 100 and 150 yard 223 in pouring rain and saw no change at all in point of impact. Not scientific but done it 3 times.

[TC95GT]

Found this-
Understanding Firearm Ballistics, by Robert A. Rinker Pg 376. "While rain can make a hunt or a day on the range miserable, it has little or no effect on the projectiles."

[gyrfalcon]

What about hail?

[farmerj]

You would have a bigger influence from temp and humidty

[Snowgun]

The bullet, assuming it's traveling supersonic, has a shockwave that travels before it, above it and to the sides that will more than likely render the effects of the rain inert.

WARNING: ENGINEER FAIL



The definition of supersonic means that the object is traveling so fast that it outruns the lead pressure wave. Think of a boat, when you are paddling the waves you make from rocking the boat are fast enough to move out in front of you. When you turn on the motor, all you see is wake behind you.

The Picture above shows the Hornet piercing the pressure wave as it hits the sound barrier.

More awesomeness


There is a shock wave:

When an object (or disturbance) moves faster than the information about it can be propagated into the surrounding fluid, fluid near the disturbance cannot react or "get out of the way" before the disturbance arrives. In a shock wave the properties of the fluid (density, pressure, temperature, velocity, Mach number) change almost instantaneously.

But it won't effect what the lead point of the object hits, or act like a force field...

[Stradawhovious]

Don't trouble me with technicalities.

This doesn't change the fact that rain will not have an effect ln the POI.

How do you explain it, Dr. Science?

[Snowgun]

I think this would be interesting to experiment on...

One could make raindrops by using straws and various surface tension surfactants, making a bubble of water on top of a straw statically. Then , putting a rifle on a lead sled, you could shoot with and without the water...

Or one could just run a hose or sheet of water in front of the gun...

[Snowgun]

:blah:


Don't trouble me with technicalities.

This doesn't change the fact that rain will not have an effect ln the POI.

How do you explain it, Dr. Science?

You don't know that for certain....

I imagine that the rain causes the standard deviation of bullet impact point to increase and widen. Not necessarily in any direction, therefore you wouldn't notice it unless you where shooting lots of samples.

Essentially, I predict that rain would increase your MOA error (not POI), since the bullet would be hitting tops, bottoms and sides of raindrops as it flew. This would probably be minimal though depending on time of flight and density of raindrops...

[Stradawhovious]

:blah:


Don't trouble me with technicalities.

This doesn't change the fact that rain will not have an effect ln the POI.

How do you explain it, Dr. Science?

I imagine that the ............

Essentially, I predict that.........

So what you're saying is that you don't know either.

[mnmike59]

The bullet, assuming it's traveling supersonic, has a shockwave that travels before it, above it and to the sides that will more than likely render the effects of the rain inert.

I heard that about your driving, But not Bullets!

[Snowgun]

Check it out 7.57 m/sec compared to a 3000 fps bullet (914 m/sec). The raindrops would essentually be frozen in place during the bullets flight, so it would most likely be a funcion of rain density over the caliber diameter and distance. So probably pretty light since all you guys wouldn't be shooting in a torrential downpour...

[Snowgun]

So what you're saying is that you don't know either.

Of course! everything is a theory until proven wrong, that's why I didn't make any definitive statements like,

This doesn't change the fact that rain will not have an effect ln the POI.