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Effect of rain on accuracy? (At 100 yards)

Planned all week around shooting this weekend. Been working up a 77 SMK moly load for new Kreiger 20" in Barnes Precision AR-15. Raining now as I sit at kitchen table with chargemaster throwing charges in prepped brass. Have 28 of the most uniform pieces I've made. Trimmed to 1.745" on Forster, wt sorted Lapua within a grain, tumbled, fresh chamfer/deburr, etc.

Trying to replicate my best group last week, a seven shot 0.501". Am I wasting my time (and Varget) shooting this weekend if the rain continues as called for? Range has a nice covered roof. I work M-F and with small kids at home, it's not as easy to shoot as it used to be. I'm eager, but don't want to waste my time or components if rain will effect my groups in an appreciable way.


Dan
 
Great question! Shoot as you would any other time....still be mindful of the wind (hopefully with flags). However, rain pouring off the roof in front of the muzzle ( i.e. a waterfall) = NFG..........and I don't like to shoot if the rain starts blowing into the muzzle, and keep the ammo and chamber dry. Most likely will not affect group size, but probably will affect POI.
 
Shot some of my best groups in the rain! I can't remember the article but it said the rain never touches the bullet due to the air turbulence surrounding it or something along that lines. Give a shout to Brian Litz and he could explain it.
 
MrMajestic said:
Shot some of my best groups in the rain! I can't remember the article but it said the rain never touches the bullet due to the air turbulence surrounding it or something along that lines. Give a shout to Brian Litz and he could explain it.

It is not air turbulence - it is simply that there are not enough rain drops to hit one.. the chance of hitting a rain drop are on the order of a billion to one.
 
With a time of flight of 0.12 seconds, the bullet does not really encounter that many raindrops. If it's raining too hard you can't see the target anyway.
I agree, some great shooting can be had in a light rain, or drizzle.
FWIW, Registered BR matches are not "called" for rain (other than when lightning is present), and unless a thunderstorm hits in your relay, some very respectable group aggs and scores are turned in.
 
CatShooter said:
MrMajestic said:
Shot some of my best groups in the rain! I can't remember the article but it said the rain never touches the bullet due to the air turbulence surrounding it or something along that lines. Give a shout to Brian Litz and he could explain it.

It is not air turbulence - it is simply that there are not enough rain drops to hit one.. the chance of hitting a rain drop are on the order of a billion to one.

I've heard that explanation thrown around before, but think it is implausible. I fall into the air turbulence theory myself. One could ask an F15 pilot if the windshield ever gets wet @ Mach 2?
Like I said, a great question.
 
LHSmith said:
CatShooter said:
MrMajestic said:
Shot some of my best groups in the rain! I can't remember the article but it said the rain never touches the bullet due to the air turbulence surrounding it or something along that lines. Give a shout to Brian Litz and he could explain it.

It is not air turbulence - it is simply that there are not enough rain drops to hit one.. the chance of hitting a rain drop are on the order of a billion to one.

I've heard that explanation thrown around before, but think it is implausible. I fall into the air turbulence theory myself. One could ask an F15 pilot if the windshield ever gets wet @ Mach 2?
Like I said, a great question.

Huh... the drops hit the windshield and are blown off - sit in the front seat of a plane some time.

When you calculate the actual amount of water in the air, in a 1/4" tunnel that exists for less than a second.... and you get the numbers.
 
expiper said:
OP,,,the big problem with rain is when a rain drop get in the bbl ,,,the bullet goes crazy ,,,,Roger

Or on the brass, you'll wonder who swapped your loads out for overpressure ones.
 
I've shot 100's of rounds in heavy rain, with no noticeable effect on accuracy or poi, even at long range. Lots of good groups and consistent hits out to 900+ yards. I'm not buying that the bullet never encounters a rain drop out of pure probability... No way... That 208 gr AMax out of my 308 win at 900 yards is covering a pretty big arc of sky and has a lot of hang time not to encounter a single rain drop in 100's of shots.

And the huge, easy to see, vapor trail on those heavy rain days tells me something is going on. I'm in the camp that there is a mass of highly compressed air infront of the bullet (shockwave) as it travels through the air and that any rain drops that come into contact with that mass of compressed air are vaporized, and never touch the bullet...
 
I help run the line and help on the target crew here at Piedmont and most all the shooters here like to shoot in a light rain, we have quiet a bit of experienced shooters that compete here. ::)
 
I would like to know exactly how shooting in the rain all works out... we all got our theories, but to see/hear actual proof would be interesting...
 
There have been government studies and a lot of research on this. I have read a lot of it but am reluctant to quote from memory. But if you really want to know do some research, the information is in the archives.
 
Matches are held rain or shine. I haven't noticed rain having any effect.
As someone else said you don't want rain pouring off the roof in a sheet in front of you. That and again on the soggy targets.
Your pet load of varget maybe a little off.
 

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