Become an AGN forum member to be included in our multi-thousand dollar Monthly Airgun Giveaways! Winning is as easy as picking a number, no strings attached! This is our way of thanking you for being a part of the worlds biggest airgun forum. Yours truly, Michael Wendt - Owner.
Join HERE

Wind effect on 16g vs 18g pellets

Forums Pellets, Projectiles, Slugs, & Ammo Wind effect on 16g vs 18g pellets

  • Views : 322
  • Link

    h2okenny
    Participant
    Member
    United States
    Accuracy: +9

    I know the heavier the pellet the better it performs in windy conditions. I also know the faster it's moving the less effect wind has on it. So is there a significant different in a 16g pellet leaving the muzzle at 900 fps and a 18g pellet at 870 fps. Most of my shooting is 40-60yds so lets go with 50yds. Whadda think? 

    • This topic was modified 1 week ago by a Moderator.
    Link

    shambozzie
    Participant
    Member
    United States
    Accuracy: +27

    Cricket compact, 5 mph [email protected] 60 yds. Jsb 18.1 @ 880.

    Link

    shambozzie
    Participant
    Member
    United States
    Accuracy: +27

    At 10 & 20 mph crosswind also.

    Link

    bigHUN
    Participant
    Member
    Canada
    Accuracy: +9

    A higher speed lighter pellet will drift more then a slower heavier pellet.

    Whether a pellet drops 30" at 100 yards or 38" matters much less than if there is any wind in the equation. A wind is always less predictable vs gravity.

    Link

    bandg
    Participant
    Member
    United States
    Accuracy: +33

    "A higher speed lighter pellet will drift more then a slower heavier pellet."

    Sure seems like an overgeneralization to me.

    Link

    Stretch
    Participant
    Member
    United States
    Accuracy: +0

    h2okenny

    I know the heavier the pellet the better it performs in windy conditions. I also know the faster it's moving the less effect wind has on it. So is there a significant different in a 16g pellet leaving the muzzle at 900 fps and a 18g pellet at 870 fps. Most of my shooting is 40-60yds so lets go with 50yds. Whadda think? 

    Windage is influenced by BC.  The higher the BC the less it is affected by the wind.  Pellet weight and speed effects elevation.  The heavier the pellet and longer it is in flight the more elevation it will loose.

    Link

    18.13
    Participant
    Member
    United States
    Accuracy: +11

    And heavier doesn't always have a higher BC. A. 25 cal. 34gr pellet has a higher BC than a. 30 cal 44.75

    Link

    elh0102
    Participant
    Member
    United States
    Accuracy: +45

    The difference between the 2 is less than the error most of us make in estimating the wind. The math for calculating drift in a 10 mph,.90 degree crosswind at 50 or 100 yards is indisputable. The problem, that exact condition almost never exists. Choose the pellet that shoots best in your rifle, then practice with your wind flags.

    Link

    bigHUN
    Participant
    Member
    Canada
    Accuracy: +9

    bandg

    "A higher speed lighter pellet will drift more then a slower heavier pellet."

    Sure seems like an overgeneralization to me.

    Which part you don't understand or don't believe? :)

    Link

    pinguinu01
    Participant
    Member
    United States
    Accuracy: +3

    The opinions expressed above are all correct or all wrong :).

    Let's assume that the wind exercises a lateral force against the pellet for the duration of the pellets's flight.

    The wind force is proportional to the wind velocity and the pellet surface area that faces the wind (usually from the pellet tip to the pellet skirt).

    A heavier pellet will move less under the same wind force than a lighter pellet (try pushing a big rock and a small rock with the same force and this will become obvious).

    If the heavier pellet has a larger area exposed to the wind (larger caliber for instance) than the wind force will be higher than against a smaller pellet (a smaller caliber).

    The ballistic coefficient will determine the pellet drop in velocity at various distances. The higher the ballistic coefficient the less the drop in velocity at various distances.

    Conclusion

    The higher the ballistic coefficient, the faster the velocity, the smaller the flight duration and the less influence the wind has.

    The heavier the pellet the less influence the wind has.

    The smaller the pellet area exposed to the wind the less influence the wind has. Smaller calibers at the same weight will be less affected than larger calibers of the same weight.

    • This reply was modified 1 week ago by pinguinu01.
    Link

    Dave
    Participant
    Member
    United States
    Accuracy: +7

    h2okenny

    I know the heavier the pellet the better it performs in windy conditions. I also know the faster it's moving the less effect wind has on it. So is there a significant different in a 16g pellet leaving the muzzle at 900 fps and a 18g pellet at 870 fps. Most of my shooting is 40-60yds so lets go with 50yds. Whadda think? 

    This is probably the best to help you understand Ballistic Coefficient, which will help you understand the issue of weight difference and performance.

    https://www.airgunnation.com/topic/what-is-ballistic-coefficient/?referrer=1

    Keep in mind that just because a pellet is lighter, doesn't mean that you will always shoot it at faster speeds. Most of these pellets have a preferred velocity range where they achieve the best accuracy. This means that if your airgun is shooting 16 and 18gr pellets at their proper speeds the difference between the velocitys may be very minor.The key to understanding BC comes from the sectional density.  This is why a 34gr .22 cal will have a high BC than a 34gr .25 cal. 

    My.25 Taipan pushes the 33.95's at about 900FPS as the optimal out of my gun, and although I can push them faster, and can push the 25gr JSB even faster, they start to loose their accuracy above this point in my case. 

    Link

    SqrlHntr
    Participant
    Member
    United States
    Accuracy: +1

    Barrel twist and length are also vital in determining crosswind wind resistance for pellets, while barrel twist direction has a different effect on crosswinds, although I don't see many LH twist airgun barrels. Longer and twisty are not always better. There is also the theoretical part of a ballistics app, and a single bc entered compared to two or more is still a guess, albeit an educated one. Dont forget environmental considerations too.   The point is, without chrony data near and far and correct rifle/scope/pellet data you are still guessing. But i digress.  To compare only one weight to another to say which one is more wind resistant than the other is almost moot IMO because pellet designs and physical characteristics differ with weight.  The HN FT trophy for an obvious example. 14.6 gr and has a cone drilled into them to help reduce weight but it also changes the center of gravity a good bit towards the nose. This is totally different performing pellet than a crosman premier in the exact same weight. 
    Its not if one drifts less than another, just how much it drifts and is it consistent. 

    Link

    AndyH
    Participant
    Member
    United States
    Accuracy: +3

    Keep part of this simple. Everything falls at 32 feet per second squared no matter what it weighs. So all pellets shot at the same speed will have the same drop.

     

    Link

    Centercut
    Participant
    Member
    United States
    Accuracy: +178

    AndyH

    Keep part of this simple. Everything falls at 32 feet per second squared no matter what it weighs. So all pellets shot at the same speed will have the same drop.

    Logically and common sense wise there are many things about ballistics that are truly counter intuitive.  You might "think" that a 44.75 grain .30 caliber pellet would be affected less by the wind that a 25.4 grain .22 caliber pellet.  But you'd be  wrong in the case of the JSB RD Monsters, which have a greater BC than the  .30 cal. 44,75 grain JSB Exact.  

    You might try and apply common sense about 32 ft/secbut you'd be wrong again.  Plug in the JSB RD Monster pellet BC of 0.051 at 975 FPS at 200 yards and a JSB KO slug 25.4 grains BC of 0.084 at 200 yards and 975 FPS.  See which one drops more, even though same weight same speed…  Yup, the pellet, by a large margin.  

    All of this is primarily based on the projectile's Ballistic Coefficient.  Higher BC, less drop and less affected by wind…  In many cases, a pellet at 875 FPS will be LESS affected by wind than that  same pellet shot at 1025 FPS.  Blows your mind doesn't it?  Most pellets have a higher BC when shot at 875-ish FPS than at 1025-ish FPS.  Faster isn't always better, especially in subsonic projectiles…

    • This reply was modified 1 week ago by Centercut.
    Link

    Brent
    Participant
    Member
    United States
    Accuracy: +1

    That's because 875 ish is the sweet spot for Diablo shaped pellets and the most stable at that speed. Much faster and they will start to corkscrew and become less stable which lends to more wind drag. At least that's how I understand it, but I'm still learning and may have it a bit skewed. 

    Link

    Ghostranger169
    Participant
    Member
    United States
    Accuracy: +7

    Seems easy enough to shoot 50 yard groups of 16g @ 900 fps and groups of 18g @ 875 fps on a calm day and measure your average distance away from point of aim. Then pick a windy day and do the same. This should provide you with some good hard numbers to compare and come up with a real world answer.

Viewing 16 posts - 1 through 16 (of 16 total)

You must be logged in to reply to this topic.