I had hoped to test 6 different .257 Roberts factory loads in my Model 70 today, but it will be raining all day.

Got me to thinking, how does rain affect point of impact and accuracy?

Bushmaster1313,

Perfect day for you to teach us. Go for it in the rain.

That has always caused me wonder as well. In googling, I came up with the weight of an average raindrop as being about 1.3 grains (if I did the math correctly - it said .003 ounce, so I divided 7000 by 16 and then took that times .003). Another source said that a raindrop hits Earth with a force equal to 349 X its weight. That comes out to about 454. Naturally, I don't have the faintest idea what any of that means. Would someone who understands this stuff and possesses great patience explain what effect one raindrop striking a given bullet (lets say a 180 grain .30 caliber starting out at 2700 fps) would have upon it? (Please try to keep it simple so that the slow among us can sort of understand the explanation - thanks in advance.)

Would it ever hit it? Pressure in front of the bullet should push it out of the way, correct?

i've heard that rain will raise POI a tad, but i have not been able to see any difference.

It dosen't do anything , the bullet is not in flight long enough,

Yet it is flight long enough for wind to affect it? Not being argumentative - I really am this dense.

My take is this...I can't for the life of me get it to change my poi @ 400 yds to less than minute of deer.

Not today.
I want to find out which factory load shoots best and I do not want to be bothered by the weather.

Correct. Based on reports from competitors, every now and again you can get a bullet to hit a rain drop (probably a really large drop, at that) that throws off the POI by a bit, but it's a very rare thing.

The pressure wave in front of the bullet, combined with the short TOF, both favour the likelihood that the bullet never touches a drop of water when you go shooting in the rain.

The wind is a constant pressure on it. Raindrops have too much space between them.

just forget it and go back to bed, you will nee the rest in the morning.

I shoot service rifle competition at distances out to 600 yds. with .223, rain, snow, or shine. I never consider the impact of the rain itself... I'm currently shooting master level scores.

If the pressure wave pushed the rain drop out of the way, Sir Isaac says that the reaction on the bullet has to be equal and opposite the reaction of the rain. That a bullet moves in the wind whose air molecules are proportionately so much less massive says the bullet will move. Because center mass of the rain drop may be randomly distributed around the axis of the bullet means the deflection may be random. Whether or not the bullet's pressure wave moves the rain drop or the rain drop does indeed hit the bullet is not relevant. A bullet fired n the rain may deflect less than a bullet fired into grass or brush, but it will deflect in the same manner with the same random dispersion.

Having found a fair number of Barnes bullets butt first embedded into trees behind my targets I suspect that a very small upset is possible and may cause them to tumble and restabilize going backwards because of the drag of the upset. I doubt the stability is very good. Of the bullets found embedded, it looked like maybe 80% went in butt first. It might well be that this sample is not representative. It may be that only Barnes TSXs are prone to doing this. It might be that only a specific kind of upset triggered by very specific conditions can cause this.

The chances of a bullet fired at a deer hitting a large raindrop and deflecting enough to matter are remote. Deer are not usually out in the open presenting longer range shots in rain that has big heavy drops. Light mist, light drizzle with small drops and snow, yes. BTDT. Never seen or heard of a deflection.

Not necessarily. The bullet itself isn't touching the rain drop. The bullet is pushing air out of the way, which pushes back (Newton's law, which we call drag), whether it's raining or not. The air then pushes against the water droplet. The reactive force of the water drop back on the air molecules would be insignificant because that pressure wave is rapidly and constantly composed of changing air molecules as the bullet travels along, rather than the same air molecules travelling with the bullet in a wave. The force that the droplet exerts on the air molecules would not transfer back to the bullet in any significant way. This is because the bullet would already have travelled passed those specific molecules by the time they make it back to where the bullet was at the time of impact with the water molecule.

If the bullet moves the drop, the drop has to move the bullet. Not an option otherwise.

The bullet doesn't move the drop. The air molecules do. That's the point. The reason that impact with a drop doesn't deflect the bullet, is that the bullet doesn't actually hit the drop, the air molecules of the air pressure wave do.

If you hold a ping pong ball on the palm of your hand, and then take a deep breath and blow it off your hand, the ball moves and flies off your hand. Does the ball exert a reactionary force on your mouth?

Aw GEEZUZ Jordan! You gotta think about things 'fore you open your mouth. The only place for the energy to move the ran drop can come from is the bullet. No ifs. No ands. No buts. If the bullet gives up the energy to move the drop, the bulloet is effected. If the bullet does not move the drop it is unaffected.

If you've ever shot in the rain or very humid air you will see a sizable "tube" of disturbed water along the bullet's path. The perturbation of all that water and the change of state you see is energy given up by the bullet.

See the displaced air forming a ">" around the bullet? No raindrop is going to touch the bullet. Any possible effect the wave has on the raindrop which in turn could effect the wave back to the bullet is moot because by the time that would happen the bullet is well past the effected air molecules that started it.



Rain has no effect on bullets. In fact I prefer to shoot in the rain. Talk about being able to see trace...

If the rain does not touch the bullet and assuming the rain drop is in the bullet's path, please explain where the energy to move the raindrop comes from.

By your logic if I smack you upside the head with a stick to help you understand this, I did nothing to you, it was that damn stick.

Pay attention! There is one place for the energy to come from. One only. The bullet.

everyone is talking about rain ,why are you attacking me personely.

Your physics is flawed. Quit arguing with everybody

The bullet transfers energy to the air around it WHETHER OR NOT IT IS RAINING. It's called drag, air resistance, or fluid resistance. Take your pick.

Ever heard of a "sunk cost" in the business world? The energy lost to creating that pressure wave ahead of the bullet, aka air resistance, is a sunk cost. A rain drop that is moved out of the way by the air molecules is moved by work done by the air, not directly by the bullet.

Another analogy to try and help you visualize this: If a jet fighter is approaching a wall (much like a bullet approaching a rain drop), and the jet fires a missile at the wall (like the bullet pushing the air ahead of it toward the rain drop), the jet loses some energy by pushing the missile, but the impact between the missile and the wall does not exert a force on the jet at all. The jet sails right through where the wall used to be (assuming it doesn't get hit by any debris). Likewise, the bullet sails right through the space where the drop used to be after the air wave pushes the drop out of the way, which air has already absorbed some energy from the bullet, drop or no drop.

Miles have you have shot in the rain? Rain has very little to no effect(even at long range) on a bullets path as long as the bullet is properly stabilized.

If the jet is flying through rain, does the rain hit it?

If the physics is wrong demonstrate where. Show me where the energy to move the rain comes from.

Already did.

Don't ask jackass questions without reading the earlier posts.

As I stated earlier until you get to the big drops the net effect s gong to be random and small. Bigger drops more deflection. Tell me hail (even bigger rain drops) won't effect it even more. If I were to take small very frangible bullets and fire them fast in large heavy rain do you want to bet on how many make it to the target?

No, you did not.

Jordan, good way of explaining everything. I'm no physics major, but I did take the class. I am 100% with you that the rain does not affect the bullet in the course that most think of. As stated it is the air (drag) from the bullet that pushes the drop. By the time the drop pushes back the bullet has traveled past the effected point. The force from the rain drop would have to be large enough to overcome the drag force in said time period to effect the bullet. I guess the question is, do we know the forces of each individual component?

Here are some thoughts I'm having leading to a question. If the rains point of impact is perpendicular to the bullets no effect would take place due to the drag, but say the bullets impact is perpendicular to the rain (think of bullet hitting the rain instead of vise versa) we would then see some type of effect to the bullet correct? If hit directly center of the rain drop we would see a velocity change, if hit anywhere else a slight shift to POI?

I'm really just rambling with all of this I feel, but interesting stuff to think about.

Aw GEEZUS!!!!

Lets start at the elementary school level.

What happens when you increase air pressure? Air gets DENSER.

What happens when you increase air pressure radically??? It gets really dense.

Consider water. If you hit the water at 10 MPH no big deal even if you do a belly flop. What happens when you increase the velocity? It continues to increase it's pain production until is disassembles your body.

When the air becomes as dense as it does when it is compressed inside the pressure envelope it becomes essentiially as incompressible as water and is no longer able to move out of the way of objects striking it. This is partly why entrance holes can be larger than bullet diameter.

When the raindrop hits the very dense air it behaves very much like the stick you get whacked upside the head with and it effects the bullet very much as if it had hit the bullet itself.

Does all this mean I really don't need windshield wipers after all??

I'm sure it has an affect on the bullet somehow but I've never really noticed...You'd probably see a noticable difference when shooting extremely long range. I've heard of extremely fast cartridges like the 220 swift bullets not even making it to the target when shooting in the rain. Maybe the guy that told me this was blowing hot air...I shoot in all kinds of weather and I kept this target from an outing in the rain (notice the paper was wet) with my all weather ruger hawkeye 308 win:



It may have affected accuracy a little bit....

Wrong. Where are you getting that information?

The bullet, air wave, and rain drop are 3 separate systems. The bullet transfers energy into the air wave system regardless of the presence of rain, or lack thereof. If a drop is placed in the path of the bullet, some energy is transferred from the air wave to the rain drop. There is no energy transferred from the bullet to the rain drop, or from the rain drop to the bullet. The air molecules act as the intermediate buffer.

If a large enough rain drop gets hit dead center by the bullet, where there is not enough air pressure to move the drop out of the way before the tip of the bullet impacts it, that situation may cause the bullet to deviate from its course. This is seen in 1000 yard competition in the rain, where they'll rarely see a bullet get dropped from the target inexplicably.

Jordan, your theory above cannot be correct and can be invalidated logically. Here is the flip side of your theory(replaced bullet with rain drop to your theory above):

"The bullet, air wave, and rain drop are 3 separate systems. The rain transfers energy into the air wave system regardless of the presence of bullet, or lack thereof. If a bullet is placed in the path of the air, some energy is transferred from the air wave to the bullet drop. There is no energy transferred from the rain drop to the bullet, or from the bullet to the bullet. The air molecules act as the intermediate buffer."


Aic

Physics isn't always a two-way street, and doesn't always play the same in forward and reverse, such as in this case. See the above posts for an explanation of what I'm saying. Formidilosus gave essentially the same explanation as I am.

Fellas, there really is no arguement. This was researched with your tax dollars by the US military. Rain does not affect accuracy. A book by Robert Rinker(?) called "Understanding Ballistics" goes into quite a bit of detail.

It's fun to argue when you know you're right based on passed experimentation and data

Now, how does snow effect your group size?


When your freezing your balls off and can't see....well, I'm not showing my target...

I'd say there is a direct correlation between snow/cold and icy balls syndrome. IBS also seems to go hand-in-hand with "numb 'n' twitchy finger" syndrome, which can certainly degrade accuracy.

I do believe that I suffer from numb 'n' twitchy finger syndrome whenever one of my rifles makes its way to a benchrest...

Just let your sister shoot it and we'll see how it really groups....

-1

It's not always the same in forward and reverse but there is always a forward and reverse...

Aic

Think improved choke...

KITB...

Well, no there's not. But in this case there is

And in this case, the reverse includes the rain drop pushing back on the air molecules, which are already behind the bullet as new molecules fill the pressure wave ahead....

Not affecting accuracy by much does not mean it does not affect� Ito has a lemma on it�

Aic

I know. I owe tanner a public apology....Sorry tanner buddy....

Here's another way of looking at it. Could be totally off of the mark, so take it for what it may or may not be.

Both the raindrop and bullet are both being acted upon by the exact downward vector (gravity), so could a raindrop really fall onto a bullet in the first place? They are dropping at the same rate. So in my eyes a raindrop couldn't effect the bullet on the vertical plane.

Now if the bullet were to potentially hit the raindrop on the horizontal plane I guess you could think of it as an arm swinging towards a feather. A direct hit would have some type of an effect but the time interval and force of such hit would be minimal (obviously the longer the bullet travels in such case the more off course it could become, but between all the factors stated previously you shouldn't see much change.)

I'm going to shoot a raindrop and see.

Kinetic energy, momentum, rain displacement, chromatic aberration..... Does anyone just shoot anymore?




To the OP- fret not, bust caps.

ha ha good point formidilosus

Ought to move this thread to the Humor, Jokes and Riddles section.

Yup.

My biggest New England whitetail came at 300 yards on a miserable day,just sopping,flat rock raining....despite its' considerable ballistic challenges,the crummy 130 gr 270 bullet hit and did considerable damage.He did a mid air 180 and landed with a huge splash in the swamp.... I was never so glad to get out of a stand....

Last year I watched my pal stick 4 175 TBBC's from a 7mm Mashburn into a 6" orange dot at 600 yards.....pouring rain that day,too. I stayed dry while he did it.

If rain changes POI or otherwise causes a problem,it's beyond my ability to observe it.

I do like to see the spurt of water off wet hides though....I watched a guy in New Brunswick shoot a buck at about 200 yards with a 270 and 130 gr bullet in the rain.At impact the water radiated out from his body in a halo as he collapsed.

I thought this was pretty good, given the cartridge and bullet's reputation on here for being the terminal equivilent of a ping pong ball...

OK. Here's the deal for you non believers.

I will set up a garden hose to produce good size "rain drops" and shoot .224 bullets through it at somewhere around or just above 3000 FPS. I will use 35 grain VMaxs and Nosler 35 grain lead free bullets.

I will take any and all bets that not only will they deflect, but that some of them will never make it to the target.

This won't be a fair test as some of your "rain drops" will likely weigh 400 pounds!

If you can explain how to make a 50 gallon rain drop hold together out of a garden hose we might entertain your objection. Otherwise, we have enough mindless drivel in this thread.

Even shooting through a small stream of water proves the concept that the shockwave is not capable of preventing alteration in bullet path until the "rain drops" become very small.

Rain drops would be a poor and humorous excuse for missing.

Anyway, I'm sure some of the competition shooters have shot tournaments in the rain while they themselves have been roofed over. Has overall or average group size increased? Has normal winning group size increased? Of course rain is often accompained with wind which would change things.

I doubt it and even if the groups have increased I'm thinking that it would be insignificantly small.

For the testers out there, remember also that you don't see the target as we'll in a good downpour and therefor you will not shoot as well.

Shooting targets out to 300yards in the rain my rifles showed no change in grouping capability.

strange topic for an optics forum
cross wind and water do not vector against the bullet, they change the drag on the other side causing the direction change. there exists a probability that the drag change could "correct" a slightly bad shot in both cases. Humidity,(clouds and such) are less dense than air and rise, (one of the reasons they are included when running ballistic programs.) The actual volume of air used by the bullet path contains both rain drops and rising air. The total volume is far greater than the volume of the actual water in the form of drops. Next the concept which includes the time of flight, mass of the bullet,bc of the bullet, and can change with each of the inputs. The probability the bullet even contacts a drop. Add to this -- its very hard to shoot long distances in the rain. Previous posts assume a collision, when the question just asks what happens when you shoot in the rain. There is a still shot on the internet of a bullet being shot thru and apple, which I enjoy. It illustrates a good point. The flight path of the bullet is barely affected. Because the apple is very homogeneous and the drag forces are equal at every point on the bullet. therefore no deflection. (except slower velocity) The same happens with a rain drop. Unless the density of the rain drop is enough to start bullet expansion, (and change the drag on one side) no effect will be made on the bullet .
Please no post about skipping bullets off rain drops.

edit to take out math

MILES58: Take my advice and DON'T bet a lot of your dollars on your contention!
For DECADES I shot at the Seattle (Duwamish) SPAA Range on the tide flats on the south edge of that city.
I sometimes shot 3 or 4 times per week - often, VERY OFTEN, it would be raining!
Sometimes raining hard.
I shot a plethora of high speed centerfire Rifles/cartridges including 220 Swift, 17 Remington, 6mm Remington Ackley Improved, 22-250 Remington etc etc etc.
Never once did I have a projectile fail to reach the target - nor could I ever once attribute a loss of accuracy (blown group) to any watery climatic condition - usually I caught myself flinching or jerking the trigger when a shot placed outside the normal grouping.
I am about 99% certain that rain drops do not affect a speedy bullets flight - at least out to 100 and 200 yards as I have shot many thousands of them in such conditions.
This contention of mine is based entirely on my own personal experience as I don't recall ever reading any scientific studies done on this bullets in the rain situation.
I could be wrong but I don't think so - I will only bet you $1.00 (U.S.) on the outcome of your hose making rain vs. bullet flight testing.
I say the bullets will not be affected by droplets - they of course would be affected by flying through a stream or a flow of water.
Interesting question - if perhaps unanswerable?
Hold into the wind
VarmintGuy

for those that do not believe it is possible for a fast 6 mm bullet to hit a rain drop.

i know of a video taken at a very large shoot that clearly shows a great group ruined on the last shot when the bullet hit a drop of water. you can see it hit and the result was a low shot [ that did hit paper ]

my guess is the results are random. i feel fairly certain i have hit raindrops when shooting in the rain, but without proof i usually chalk it up to sticky bags and the like causing the vertical. i do not remember any that did not reach the target.

a sticky bag can cause at least a bullet hole of vertical and make it hard to detect if the bullet hit something or not. if you get a couple inches at 200 yd that's different from bad form or bag set up.

I too have never found any detriment to accuracy shooting in the rain. I know that shooting through even 1/4" of water will fragment a Hornady 50 grain SPSX bullet at 3500+ fps. I have shot in a lot of rain and never lost a bullet in flight. I do like being able to see the wind when shooting in rain and snow.