The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: General

Reply
 
Thread Tools Search this Thread
Old March 17, 2016, 09:16 PM   #1
Lwh4207
Member
 
Join Date: January 9, 2016
Posts: 50
Rain affecting bullets

How much will rain, fog, or heavy moisture in the air effect small high velocity bullets such as a 22-250.
Lwh4207 is offline  
Old March 17, 2016, 09:50 PM   #2
reynolds357
Senior Member
 
Join Date: December 10, 2012
Posts: 6,161
A tremendous amount at long range.
reynolds357 is offline  
Old March 17, 2016, 10:01 PM   #3
James K
Member In Memoriam
 
Join Date: March 17, 1999
Posts: 24,383
Some reports I have seen say the opposite, little or no effect even on light bullets. Now rain may be accompanied by wind and that will certainly affect bullets, but ordinary rain seems to have little effect since the actual drops are separated by both time and space.

Jim
James K is offline  
Old March 17, 2016, 10:57 PM   #4
Jim Watson
Senior Member
 
Join Date: October 25, 2001
Location: Alabama
Posts: 18,487
I have only been called on to shoot in the rain a few times.
I found that the rain affected me a lot more than it did the bullets.
When I could ignore the rain, I got a center hit.
Jim Watson is offline  
Old March 17, 2016, 11:46 PM   #5
kilimanjaro
Senior Member
 
Join Date: November 23, 2009
Posts: 3,963
Denser air will slow the bullet and cause greater drop, can't say how much. Range is the bigger factor in the equation.
kilimanjaro is offline  
Old March 17, 2016, 11:58 PM   #6
FrankenMauser
Senior Member
 
Join Date: August 25, 2008
Location: In the valley above the plain
Posts: 13,402
I've never seen rain cause a problem.
And most people that have studied the concept conclude that the aerodynamic shockwave will disrupt the raindrop with little to no impact on the bullet's flight.

A few years ago, I did the math for the odds of hitting a rain drop in a two-inches-per-hour rain storm.

My conclusion (assuming constant velocity):
A .308" diameter bullet traveling at 2,100 fps to a 100 yard target has just a 0.0139% (1:7175) chance of hitting a rain drop.
The smaller the bullet, the better the odds.
The faster the bullet, the better the odds.
A .224" bullet traveling at 3,900 fps has only a 0.0054% (1:18,323) chance of hitting a rain drop in a two-inches-per-hour rain storm.

And the jury is still out on whether or not the rain drop would even matter.


High humidity... I honestly don't know.
Instinct tells me that a denser atmosphere will cause more drag and slow the bullet more quickly; but ballistic calculators spit out higher velocities (and subsequently less bullet drop) with higher humidity levels.
__________________
Don't even try it. It's even worse than the internet would lead you to believe.
FrankenMauser is offline  
Old March 18, 2016, 05:45 PM   #7
g.willikers
Senior Member
 
Join Date: September 28, 2008
Posts: 10,442
Out in the real world, there's probably going to be more stuff in the way of the bullet than rain drops.
If you ever take a shot and are mystified why nothing hit the target, check to see if there's maybe a hard to see tree branch or something in the flight path.
Since we live in an area of very high summer humidity, about the only thing the humidity seems to cause is being able to sometimes actually see the bullet in flight.
Very cool.
__________________
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”
g.willikers is offline  
Old March 18, 2016, 06:39 PM   #8
g.willikers
Senior Member
 
Join Date: September 28, 2008
Posts: 10,442
Well dang, almost forgot the funny story about having things in the way of the shot.
At a rifle match with targets at an undeclared distance, one poor guy was having a heck of a time.
He keeps adjusting and readjusting his scope and getting absolutely nothing on target.
All the while the RO who is viewing everything through a very large spotting scope is chuckling away every time this fellow takes a shot.
After awhile the RO moseys over to the guy and kind of casually asks how he's doing.
After hearing all the fellow's complaints about his malfunctioning scope or crappy ammo, he takes pity on the guy and invites him to take a look through the spotting scope.
It turns out there's a good sized tree blending in so well with the background that it's practically invisible.
And it's right in the path of every shot the guy has been taking and stopping or deflecting every shot.
Tree scored 100, target scored 0.
__________________
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”
g.willikers is offline  
Old March 18, 2016, 06:51 PM   #9
Brian Pfleuger
Moderator Emeritus
 
Join Date: June 25, 2008
Location: Austin, CO
Posts: 19,578
The question has come up many times. Here is my answer from several years ago:

http://thefiringline.com/forums/show...9&postcount=26

Quote:
There's not nearly as much water in the air during a rain storm as some folks seem to believe.

Let's just use a simple thought process as an example. It may not be perfectly scientifically, mathematically correct but it's close enough to give you an idea.

Let's say it's raining at a very heavy 5 inches per hour. This is at least 20% higher than, and more likely 2-5x higher than, an average rain fall.

To get a really good number and put everybody to sleep, we'd have to use some fun calculus (Δt → 0) and other fun stuff.

I'm going to guesstiproximate instead.

Let's go with a 180gr .308 bullet at 2,600 fps MV. That bullet (according to JBM Ballistics) would take about 1.9 seconds to get to 1,000 yards. Let's call it 2 seconds for easy math.

Let's do some simple extrapolation,

A 5"/hour rain fall literally means that it takes one hour to fill a space with 5" water. There are 3,600 seconds in an hour. The bullet is in flight to 1,000 yards for 2 seconds. During that 2 seconds, only 2/3600ths of the total 1 hour rain will fall. That means that during the entire bullet flight time, the total amount of water in the air is 5 inches x 2 divided by 3,600 seconds. That's 1/360th of an inch (~0.0027777) of rain in that time. That amount is broken up evenly throughout the entire space.

Let's consider the space taken up by the bullet. Let's make it a 1,000 yard cylinder, 0.308 inches diameter. We have a cylinder 3,000 feet (36,000 inches) long with a .308" diameter. The total volume of that cylinder is 2,682 cubic inches. An average raindrop might be about 0.078 inches in diameter. That's a volume of ~0.0019877 in3.

In that 2 second flight time, we're only filling that entire cylinder with 1/360th of an inch of rain. That's a total volume of rain within that cylinder during time of flight of 0.000206955 in3.

Look at those two numbers, total volume and rain drop volume.... there's more zeros in the total volume than there are in a single rain drop!

That means that in the entire flight of the bullet, there will be less than one rain drop in it's entire path... ahead AND behind it!

Not just "less than one", a single drop of rain is almost 10 times the total volume of water in that column during the entire bullets flight!

You tell me. There's essentially 1 drop of water SOMEWHERE in the flight path of every 10th bullet. That's in front and behind. We could sort of almost consider that it would take 20 shots to get a single drop of rain to be somewhere in front of the bullet during it's time of flight.

You wanna take the bet that you're going to hit one?
__________________
Nobody plans to screw up their lives...
...they just don't plan not to.
-Andy Stanley
Brian Pfleuger is offline  
Old March 18, 2016, 07:42 PM   #10
RigidCollision
Junior Member
 
Join Date: February 21, 2016
Posts: 7
Brilliant answers guys.
RigidCollision is offline  
Old March 18, 2016, 08:44 PM   #11
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 28,677
Rain has a tremendous effect on shooting. None on the bullet.

So, calculations show that the odds of hitting a raindrop are tiny teeny small.

Odd on ran affecting your ability to see, and sight on a target are huge.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old March 18, 2016, 11:59 PM   #12
g.willikers
Senior Member
 
Join Date: September 28, 2008
Posts: 10,442
You know it's raining too hard when your holster fills up to overflowing with water.
But heck it's still only water.
Now on the other hand, if there's a huge flock of geese flying overhead.........
__________________
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”
g.willikers is offline  
Old March 19, 2016, 02:57 AM   #13
Gunplummer
Senior Member
 
Join Date: March 11, 2010
Location: South East Pa.
Posts: 3,364
I have hunted in steady downpours but never shot during a rain like that. I would have to wonder about shooting in a downpour. I have shot in freezing rain and could not see a difference. As far as figuring things out with math, there are to many variables to trust the result as written in stone.
Gunplummer is offline  
Old March 19, 2016, 08:11 AM   #14
mapsjanhere
Senior Member
 
Join Date: August 6, 2009
Location: Albuquerque
Posts: 2,832
While rain doesn't do anything on shooting a small bullet short distances it's interesting in what it does to a high speed interceptor missile fired in a storm. At 6000 ft/s it looks like the nose is getting sandblasted, losing fractions of an inch in material.
__________________
I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.
mapsjanhere is offline  
Old March 19, 2016, 09:00 AM   #15
Double Naught Spy
Senior Member
 
Join Date: January 8, 2001
Location: Forestburg, Montague Cnty, TX
Posts: 12,715
I would have to think that snow is a different matter all together.
__________________
"If you look through your scope and see your shoe, aim higher." -- said to me by my 11 year old daughter before going out for hogs 8/13/2011
My Hunting Videos https://www.youtube.com/user/HornHillRange
Double Naught Spy is offline  
Old March 19, 2016, 09:13 AM   #16
Guv
Senior Member
 
Join Date: February 24, 2012
Location: South Texas
Posts: 2,126
I think it's affect is less than all the other variables involved in a typical hunting (not bench rested) shot.

I also think Frankenmauser's statement about the aerodynamic shock waves affect on the rain droplets seems entirely possible.
__________________
Walnut and Gloss Blue, mostly!
Guv is offline  
Old March 19, 2016, 09:45 AM   #17
Lwh4207
Member
 
Join Date: January 9, 2016
Posts: 50
Thanks for the answers guys. The reason I ask is the other day it was raining hard and I took a shot at a coyote 150 yards away and missed him. I thought it was a clear shot just raining, but i guess I just flat out missed him.
Lwh4207 is offline  
Old March 19, 2016, 09:56 AM   #18
g.willikers
Senior Member
 
Join Date: September 28, 2008
Posts: 10,442
Driver error?
If we're honest, it probably accounts for more missed shots than anything else.
But in an emergency, any excuse will do nicely.
__________________
Walt Kelly, alias Pogo, sez:
“Don't take life so serious, son, it ain't nohow permanent.”
g.willikers is offline  
Old March 19, 2016, 10:38 AM   #19
30Cal
Senior Member
 
Join Date: December 3, 2002
Posts: 1,264
I've shot a couple matches out to 600yds through a downpour. The targets start sliding down the face of the cardboard when the paste loosens up. The bullet holes get enormous when the cardboard is saturated. It can pile up on the front sight and fill the rear aperture. Pretty easy to see the wake of the bullet as it heads downrange, but the rain makes no difference on where the bullet goes.
30Cal is offline  
Old March 19, 2016, 11:05 AM   #20
Lwh4207
Member
 
Join Date: January 9, 2016
Posts: 50
I was the driver lol and the shot was pretty hasty because he was on the move so I guess I just missed lol.
Lwh4207 is offline  
Old March 19, 2016, 11:13 AM   #21
briandg
Senior Member
 
Join Date: May 4, 2010
Posts: 5,468
How about this? Put a tube of .500 diameter at .5 ches per hour, how often do you expect a bullet that travels for maybe two seconds to actually strike a drop?

Any time that the air density is extremely off average your velocity at long ranges. I can't pretend to know the actual effects. One fact is that if the air is much denser it will absorb more energy as it displaces the air.
briandg is offline  
Old March 19, 2016, 11:58 AM   #22
kraigwy
Senior Member
 
Join Date: June 16, 2008
Location: Wyoming
Posts: 11,061
Rain effects the shooter, not the bullet.

Same with snow.

Humidity does effect the bullet, but not the way more people think. Humidity actually helps the bullet, doesn't retard its flight.
__________________
Kraig Stuart
CPT USAR Ret
USAMU Sniper School
Distinguished Rifle Badge 1071
kraigwy is offline  
Old March 19, 2016, 12:01 PM   #23
Lwh4207
Member
 
Join Date: January 9, 2016
Posts: 50
For some reason I was just thinking that small of a bullet going that fast that any little thing could knock it off target.
Lwh4207 is offline  
Old March 19, 2016, 12:48 PM   #24
Lwh4207
Member
 
Join Date: January 9, 2016
Posts: 50
I've just never had as good of luck with a 22-250 as I have with larger calibers. But it's also rare that I get good shooting conditions usually I am in the feed truck shooting at coyotes that are running the other way.
Lwh4207 is offline  
Old March 19, 2016, 01:35 PM   #25
Llama Bob
Senior Member
 
Join Date: January 13, 2016
Posts: 337
The thing to know about rain is that even when it's raining hard, there's very little of it actually in the air. An insanely fast rainfall is roughly 1"/minute of accumulated water - if it rained like that for 3 minutes, it would be a world record. Rain drops fall at about 40 mph, or 42,240 in/minute. That means during the hardest rain you'll never ever see the air is still 99.998% not water.

If you do get very unlucky and your bullet hits a raindrop square on, the bullet will be deflected. The desnsity of water is about 1/11th that of lead, so there's enough mass there to push the bullet around a bit.
Llama Bob is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:58 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.07166 seconds with 10 queries