How Much Does Rain Affect Trajectory?

Discussion in 'Competition Forum (All Calibers)' started by clunker, Jan 17, 2019.

  1. Bart B.

    Bart B.

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    My opinion on glacier ice...

    Its blue because water molecules absorb other colors more efficiently than blue. Another reason for the blue color of glaciers is the lack of air bubbles. Air bubbles, which give a white color to ice, are squeezed out by pressure increasing the density of the created ice.
     
  2. savagedasher

    savagedasher

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    You can get clear ice and milky looking ice
    But I don’t know what it has to do with the question asked
    LOL
     
  3. 6MMsteve

    6MMsteve Gold $$ Contributor

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    my favo tooooo!
     
  4. Dave Way

    Dave Way Gold $$ Contributor

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    Getting back to the original question, I have shot some, and probably most of my smallest groups in a light rain. The reason is simple, conditions are pretty much neutralized. This has been with 6mm PPC's, 6mm Taldog's, 6mm Dashers, 6.5x47 Lapua's and 300 WSM's at ranges from 100 to 1,000 yards. I will even wait out a thunderstorm. Often it is dead calm afterward-perfect for evaluating a load or your form. As far as adjusting your shooting, if you can keep your cases and eyepiece dry, you should be fine.
     
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  5. dougridgeore

    dougridgeore

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    Why would the conversation circle around what happens after the bullet leaves the barrel? Nothing a shooter can do laying behind the rifle is going to change the bullet after it leaves the muzzle.... why not discuss the issue of placing a wet case in your chamber and firing it verse shooting dry cases.... that is something that a shooter can control during a rain storm. I come to this forum to find information from experience shooters to make me a better shooter and btw I have 3 (F-class) Highmaster cards and still everyday I come to this forum and learn something new. Would someone care to expand on the consequences of shooting wet cases, what happens? and how does that effects the trajectory of that shot? Maybe a tip on how to keep things dry for some of the less experienced shooters that come to this forum for tips.
     
  6. Warren Dean

    Warren Dean Team Savage F-T/R Silver $$ Contributor

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    There isn't one that I'm aware of. :) But I would say
     
  7. Dave Way

    Dave Way Gold $$ Contributor

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    I hope I don't offend you but one thing to remember is that there are shooters of many disciplines on this site. My thing is benchrest, I don't even know what a Highmaster card is. Back issues and prior surgeries prevent me from shooting your chosen sport. You may want answers but those who have not shot in your sport are at a disadvantage as to how to help you or give you those tips you seek. In benchrest, we usually have some protection from rain.

    As far as why wet cases give flyers, and I have seen that, I can't be sure but I have a theory. My assumption is that the grip that normally takes place as the case expands is lessened if the case is wet. This would change the normal ignition sequence slightly. Anything that changes that timing will change the bullet exit timing, harmonics etc. and thus possibly trajectory and point of impact. The same thing will happen if you leave sizing lubricant on a case or if you fail to dry a chamber completely after cleaning.

    Dave.
     
  8. Turbulent Turtle

    Turbulent Turtle F-TR competitor

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    It's the only way to make rabbit food palatable.
     
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  9. alinwa

    alinwa

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    Ummmm, maybe because this is the OP's question maybe" "How does rain affect TRAJECTORY?"

    At least that's what I'M going with....

    You'se guys are gonna' all hate me for this but I truly believe that in most cases where shooting in the rain (I shoot in the rain A LOT) affects trajectory it makes shots hit LOW....

    In the BR realm (ooops, all you'se Creedmutts just cover your ears and look the other way, ain't no Talismans in this realm) it's generally accepted that while it's raining everybody has to go UP a couple cliks because the rain makes your poi drop a little. Like an inch at most.

    And In My Opinion (prime y'er guns all ye's haters) the reason the bullets hit LOW is because the raindrops swishing down create a WIND or a downdraft.......(I know, I know, e'body say "but where does this "wind" GO???")

    I get it.....

    But this is truly what I believe.

    Raindrops create a downdraft.

    There.... I said it.


    Now..... as far as moisture inside the system. In MY case using MY equipment I can state unequivocally that any hint or trace of moisture in my gun will blank primers and wreck my cases and generally ruin my day. I used to cool my barrel by pumping water thru, I have an elaborate setup which works extremely well but I had to quit using it because I flatout could NOT dry stuff out in the 10min between relays. The tinyest, teensiest weensiest drop of moisture in MY system will lock it right up.

    DAN'rous...
     
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  10. Medic505

    Medic505 Dean Wheeler Gold $$ Contributor

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    So, does that get you free coffee at McDonalds?
     
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  11. Bc'z

    Bc'z Gold $$ Contributor

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    For a dollar
     
  12. 6MMsteve

    6MMsteve Gold $$ Contributor

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    that would be free coffee and 2 eggmcmuffies
     
  13. rardoin

    rardoin Silver $$ Contributor

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    Tough crowd :D.

    Al, I think your 'downdraft theory' holds water...no pun intended:).
     
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  14. Bart B.

    Bart B.

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    That can increase thrust on bolt face, water can act as a lubricant. Pressure curve will be the same as normal
     
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  15. ED3

    ED3 Gold $$ Contributor

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    Water is indeed a lubricant under many circumstances.
    However I believe the concern about shooting wet ammunition is the fact that when heated by firing the round, the water rapidly becomes super-heated steam, which can expand to 1700 x the volume of water.

    In other words, a coating of water 0.001" on the cartridge, would expand to a volume approx 3-1/2 " in diameter at atmospheric pressure.
    Since it can't expand and escape as quickly as it is generated, it creates a very high pressure around the cartridge, including the neck - compressing/ crimping the neck, making neck tension catastrophically high.
     
    Last edited: Jan 21, 2019
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  16. ED3

    ED3 Gold $$ Contributor

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    That's an excellent (and heretofore overlooked) point regarding rain induced downdrafts. It is known that rain in thunderstorms is one cause of the miccro-burst downdrafts that creates the wind shear potentially deadly to landing aircraft.
     
  17. Immike

    Immike Gold $$ Contributor

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    I’m saving this one for an excuse... did anybody see a plane go down?
     
    Last edited: Jan 21, 2019
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  18. ED3

    ED3 Gold $$ Contributor

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    Good luck with that.
    A constant rain would likely create a steady-state condition...although that down-drafting air does eventually 'mushroom' out near the ground, creating a variety of wind conditions....so there's that.
     
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  19. Immike

    Immike Gold $$ Contributor

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    I’m thinking it can make the target appear lower also... low hits in a down pour. I haven’t experienced what Skip described but I’m not surprised by it either.
    I was living in Dallas when that plane hit the highway...
     
    Last edited: Jan 21, 2019
  20. Bart B.

    Bart B.

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    Nobody I know of compensates for the cross wind speeds each foot above the line of sight that varies with terrain. Crosswinds at trajectory peak (near 60% of target range) can be near 50% faster than where the rifle is.

    A given wind in only the first third of target range causes more drift on target than the same wind in only the last third.
     
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