Why do i have to aim my 1911 low at 50 yards

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  • harokyle

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    Sep 19, 2011
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    ok i am trying to figure out why i have to aim at the bottom of a fifty yard target to hit it. why i think this happens is that fixed handgun sights are actually set to aim a little higher than the muzzle is actually pointing at to compensate for bullet drop. This would give you a zero at say 15-20 yards. and i think at say 50 yards the sights are actually pointing too high because the bullet hasnt droped enough. Any thoughts?
     

    IndyGunner

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    I have a similar question. I havent had that experience... but I just put xs big dot sights on... they say 0-15 the dot is spot on. After 25 yards you need to use the top of the dot.... I thought bullet drop meant I need to aim ABOVE the target, not below it.


    24-7-align.gif


    xs-24-7-1.jpg
     

    45calibre

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    Jul 28, 2008
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    I have a similar question. I havent had that experience... but I just put xs big dot sights on... they say 0-15 the dot is spot on. After 25 yards you need to use the top of the dot.... I thought bullet drop meant I need to aim ABOVE the target, not below it.


    24-7-align.gif


    xs-24-7-1.jpg

    that also always confused me.
     

    IndyGunner

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    I havent been able to figure it out. I understand using the top of the dot for more precision rather than the big dot itself.... but wouldnt you aim higher? I dono... Its on a glock 27 so I dont plan on shooting a 3 inch barrel .40 cal at 50 yards anyway.
     

    Jeremiah

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    sights are generally set to shoot point of Aim at 25 yards. as they are above the barrel you must tilt the gun up,( measure the slide to top of front sight, and slide to top of rear sight) by having a shorter front sight than rear sight. As the standard handgun round doesn't drop much between 0 and 50 yards this slit tilt up, means you are "pointing" the bullets path above the point your sights are aiming at.

    http://www.google.com/imgres?imgurl...6-sTv2WG8L00gGM0vmeDw&ved=0CEsQ9QEwBA&dur=199 look at this, imagine your pistol is Zeroed at 50 yards, the bullet will continue to rise until 100~ yards. SO to hit where you want to, you need to compensate for the bullets flight path. Thus you need aim on at 50, low at 100, on at 150, then compensate for drop past 150. of course that bullet path chart isn't for .45 acp. but the logic is sound.
     

    IndyGunner

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    sights are generally set to shoot point of Aim at 25 yards. as they are above the barrel you must tilt the gun up,( measure the slide to top of front sight, and slide to top of rear sight) by having a shorter front sight than rear sight. As the standard handgun round doesn't drop much between 0 and 50 yards this slit tilt up, means you are "pointing" the bullets path above the point your sights are aiming at.

    http://www.google.com/imgres?imgurl...6-sTv2WG8L00gGM0vmeDw&ved=0CEsQ9QEwBA&dur=199 look at this, imagine your pistol is Zeroed at 50 yards, the bullet will continue to rise until 100~ yards. SO to hit where you want to, you need to compensate for the bullets flight path. Thus you need aim on at 50, low at 100, on at 150, then compensate for drop past 150. of course that bullet path chart isn't for .45 acp. but the logic is sound.

    If I had more rep id give it to ya!
     

    harokyle

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    Sep 19, 2011
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    sights are generally set to shoot point of Aim at 25 yards. as they are above the barrel you must tilt the gun up,( measure the slide to top of front sight, and slide to top of rear sight) by having a shorter front sight than rear sight. As the standard handgun round doesn't drop much between 0 and 50 yards this slit tilt up, means you are "pointing" the bullets path above the point your sights are aiming at.

    http://www.google.com/imgres?imgurl...6-sTv2WG8L00gGM0vmeDw&ved=0CEsQ9QEwBA&dur=199 look at this, imagine your pistol is Zeroed at 50 yards, the bullet will continue to rise until 100~ yards. SO to hit where you want to, you need to compensate for the bullets flight path. Thus you need aim on at 50, low at 100, on at 150, then compensate for drop past 150. of course that bullet path chart isn't for .45 acp. but the logic is sound.
    that was exactly the answer i was looking for and confirmed what i was already thinking thanks for the post
     

    barrelmaker_2002

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    I think you might look at your sight adjustment. With a 230 grain bullet at 850 fps at the muzzle, a .45 sighted in to shoot to point of aim at 20 yards, will hit more than 3" lower at 50 yards.

    Sighted in at 100 yards, it would hit about 5" high at 50 yards.

    Go here: Handloads.Com Ballistic Calculator

    Inputs are:
    velocity - 850fps
    wt. - 230 grains
    sighted at - 20 yds
    Ballistic coef. - 0.142
    St ht - 0.45
    Intervals - 10
    Max - 100
    muzzle elev. - 0
    temp - 65
    rest are zeros

    Play with the sighted in at input and you see the change in point of impact at various ranges.
     

    IndyGunner

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    barrelmaker.... I dont understand how to use that. Could you PLEASE do me a favor and explain

    speer gold dot 180 grain .40 Muzzle velocity: 985 fps

    and

    Hornady critical defense 165 grain .40 Muzzle Velocity: 1175 fps

    I dono what to add for the other variables and would greatly appreciate it.
     

    barrelmaker_2002

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    barrelmaker.... I dont understand how to use that. Could you PLEASE do me a favor and explain

    speer gold dot 180 grain .40 Muzzle velocity: 985 fps

    and

    Hornady critical defense 165 grain .40 Muzzle Velocity: 1175 fps

    I dono what to add for the other variables and would greatly appreciate it.

    Enter the bullet diameter, weight and bullet shape (SWC/HP in this case) in the ballistic coefficient calculator on the left. That will prefill those values in the main table. Then enter muzzle velocity. Most of the rest of the variables can be left as default, though I usually set the wind to 0.

    Looking at the rest of the values:

    Sighted in at: the distance your gun will shoot to point of aim at, based on how your sights are adjusted.

    Sight height: Height from the center of the bore to the top of the front sight. For a pistol, 0.5" is about right. You can use caliper or a ruler for a more precise measurement. My carry gun is 0.44" for example. My AR-15 is 2.6". Or may 2.5', I cannot remember.

    Intervals: the interval in yards the results will be reported as.

    Max Range: The furthest distance reported. For a pistol, 100 yards should be good.

    Muzzle elevation: The angle (in + or - degrees) from the horizontal plane the muzzle is elevated or declined. Usually you would assume your muzzle is level and thus zero is good.

    Temp: temp of your shooting session. Default value usually works as it takes very large temperature change to make a difference, especially at short ranges.

    Elevation: The default is usually good since, it takes a large change to make a even a small differnece. If you want, you can query your zip code and get an elevation here: Zip Code Directory FAQ. My zip code (47904) is 549 feet, for example.

    Wind speed: I usually use zero.

    Wind direction: I usually use zero. It is measured as a circle that you are the center of. So 90 degrees is a crosswind from the right and 180 degrees would be a tailwind.

    So for the gold dot, sighted in at 25 yards, your point of impact will be about 13" low at 100 yards. Total drop will be more, since the bullet rises as it comes out of the barrel and then drops/

    For the HCD, the drop at 100 yards will be about 10 inches. Lighter bullets drop less.

    More details in the instructions - click the link on the left (below the ballistic coefficient table).

    The temp and elevation values matter more with a rifle at longer ranges. Plus, you will see a range of variation equal to the typical group size of your gun at various ranges.
     

    slow1911s

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    Apr 3, 2008
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    Indianapolis
    I think you might look at your sight adjustment. With a 230 grain bullet at 850 fps at the muzzle, a .45 sighted in to shoot to point of aim at 20 yards, will hit more than 3" lower at 50 yards.

    Sighted in at 100 yards, it would hit about 5" high at 50 yards.

    +1 The 45 ACP, and just about every other non-magnum handgun round is, if aimed dead horizontal, is falling the moment it leaves the barrel. This is why PPC shooters use a neck hold on a B27 at 25 and a head hold at 50 yds. With a 25 yd zero, the bullet drops 2.5-3" at 50 yds (the bullet travels upwards from the barrel to 25 at zero, then falls 2.5-3" at 50 yds.) If one considers how fast the bullet is moving (it's still going 810 fps at 50 yds), the bullet is falling like a stone.

    Has the front sight been replaced? Is it too short?
     

    Indy_Guy_77

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    Apr 30, 2008
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    +1 The 45 ACP, and just about every other non-magnum handgun round is, if aimed dead horizontal, is falling the moment it leaves the barrel.


    It's not "just about every other". It IS every other.

    Every. single. one.

    If a given barrel is perfectly parallel with the ground, and you drop a bullet from the same height as the chamber at the precise instant you fire the weapon, both bullets will impact the ground at the same time (provided that the ground doesn't change elevation).

    Simple physics. Gravity is ALWAYS pulling with the same force (for this application, anyhow) no matter if one object is also moving forward.

    -J-
     
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