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Explain 'sight radius' of a gun,,,

montanajoemontanajoe Forums Admins, Member, Moderator Posts: 58,009 ******
edited September 2015 in General Discussion
Thank you.
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    montanajoemontanajoe Forums Admins, Member, Moderator Posts: 58,009 ******
    edited November -1
    How is this important,how does it matter??
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    roswellnativeroswellnative Member Posts: 10,127 ✭✭✭✭
    edited November -1
    I can hit a bullseye with my 7 1/2 colt
    I can't hit sh! With my 2 " Bodyguard
    The sights are identical, it's the distance between them that makes the difference
    Longer is better, at least that's what mrs Ros says

    Ros
    Although always described as a cowboy, Roswellnative generally acts as a righter of wrongs or bodyguard of some sort, where he excels thanks to his resourcefulness and incredible gun prowesses.
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    montanajoemontanajoe Forums Admins, Member, Moderator Posts: 58,009 ******
    edited November -1
    Great info. Thank you guys. [^][^][^]
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    Ray BRay B Member Posts: 11,822
    edited November -1
    It matters as a multiple of the distance to the target and the affect of errors in alignment. Example: a rifle with a distance between the front and rear sight of 2 feet. At 200 yards that is a multiple of 300. If you are 1/16th of an inch out of alignment the path of the bullet will move 1/16th" for each multiple, 300. 300/16 = 18.75", Probably miss or wound a deer but would be on a large target at about the 2 ring.
    Same thing with a handgun, distance between sights 6 inches. Multiple at 200 yards is 1200; 1/16th" x 1200 = 75 inches, that's over six feet. the deer probably wouldn't even know anyone was shooting at it and probably not even punch paper except possibly the next target.
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    1911a1-fan1911a1-fan Member Posts: 51,193 ✭✭
    edited November -1
    allegedly, a bullet is set on its path within 2" of a barrel, the sight radius of a rifle is what makes it more accurate {along with higher velocities}




    perry shooter can probably explain this pic a bit better, but its pretty self explanatory



    BoMarEFSa.jpg
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    fishkiller41fishkiller41 Member Posts: 50,608
    edited November -1
    Longer sight separation = Better accuracy. Shooting at a moving target,with a single projectile, is made more difficult by the larger separation of front and rear sight.
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    Ray BRay B Member Posts: 11,822
    edited November -1
    quote: Shooting at a moving target,with a single projectile, is made more difficult by the larger separation of front and rear sight.


    this must be the same theory about using a "low" power scope because a "high" power scope shows all of the shooters wobbles.
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    fishkiller41fishkiller41 Member Posts: 50,608
    edited November -1
    quote:Originally posted by Ray B
    quote: Shooting at a moving target,with a single projectile, is made more difficult by the larger separation of front and rear sight.


    this must be the same theory about using a "low" power scope because a "high" power scope shows all of the shooters wobbles.
    A scope changes the whole ball game.U are severely limited because U have nearly ZERO peripheral vision.It's like shooting with blinders on.
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    select-fireselect-fire Member Posts: 69,453 ✭✭✭✭
    edited November -1
    Longer sight radius..longer barrel.. more velocity.
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    bullshotbullshot Member Posts: 14,339 ✭✭✭✭
    edited November -1
    quote:Originally posted by forgemonkey
    Joe,,,,,,,here's the formula for sight correction,,,,,,courtesy of Brownell's

    Correcting Sight Height
    If your rifle or pistol is shooting high or low, there is a formula you can use to determine what the correct height for your sight should be.

    Terms
    Amount of Error: Measure in inches the distance from the bullseye to your shot.
    Sight Radius: Distance in inches from the front sight to the rear sight. *
    Distance to Target: The distance in inches from your shooting position to the target.

    Note: Be sure that your rear sight is at its mid-point before you shoot.

    Formula

    Amount of Error X Sight Radius
    = Sight Correction Needed
    Distance to Target
    If you are shooting low, you would replace your front sight with a lower sight, and conversely, if you were shooting high, then you would replace your front sight with a higher sight. Add or subtract the number of thousandths needed to the actual height of your sight and you will have the correct height of the replacement sight.

    Example
    At 100 yards, your shot is 6" low and the distance between your front and rear sight is 19.5".

    6 X 19.5
    = .0325
    3600
    Since you are shooting low, you would need to lower your front sight by .032".

    * For rifles, you measure the front sight height from the bottom of the dovetail to the top of the sight. For pistols you measure the height of the blade only. This is true unless stated otherwise in the sight specifications.


    Woody, I don't understand this math. No way it's correct as written.
    What am I missing?
    "Just because you're paranoid doesn't mean they're not out to get you"
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    NeoBlackdogNeoBlackdog Member Posts: 16,651 ✭✭✭✭
    edited November -1
    quote:Originally posted by bullshot
    quote:Originally posted by forgemonkey
    Joe,,,,,,,here's the formula for sight correction,,,,,,courtesy of Brownell's

    Correcting Sight Height
    If your rifle or pistol is shooting high or low, there is a formula you can use to determine what the correct height for your sight should be.

    Terms
    Amount of Error: Measure in inches the distance from the bullseye to your shot.
    Sight Radius: Distance in inches from the front sight to the rear sight. *
    Distance to Target: The distance in inches from your shooting position to the target.

    Note: Be sure that your rear sight is at its mid-point before you shoot.

    Formula

    Amount of Error X Sight Radius
    = Sight Correction Needed
    Distance to Target
    If you are shooting low, you would replace your front sight with a lower sight, and conversely, if you were shooting high, then you would replace your front sight with a higher sight. Add or subtract the number of thousandths needed to the actual height of your sight and you will have the correct height of the replacement sight.

    Example
    At 100 yards, your shot is 6" low and the distance between your front and rear sight is 19.5".

    6 X 19.5
    = .0325
    3600
    Since you are shooting low, you would need to lower your front sight by .032".

    * For rifles, you measure the front sight height from the bottom of the dovetail to the top of the sight. For pistols you measure the height of the blade only. This is true unless stated otherwise in the sight specifications.


    Woody, I don't understand this math. No way it's correct as written.
    What am I missing?




    (6 x 19.5)/3600 = .0325
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    onepopperonepopper Member Posts: 1,825 ✭✭✭✭✭
    edited November -1
    I'm going to put my 2 cents in this topic. The most important part of precise target shooting with a pistol is the concentration of your eye sight on the front sight. If you look at the target, instead of the front sight you will never become a precision shooter. The front sight must be sharp in your vision while aiming. Here is a little bit of information that might be useful to 1911 A1 match shooters. If you set your sights at 25 yds to hold 6 0'clock black, you then can hold center at 50 yds. Now comes the kicker---at 2 hundred yds, holding center hold on a 8" target and holding 1/2 of the front sight over the rear sight you will be right on. Now this only works with a 45 NM match pistol shooting regular hard ball ammo. I can't remember how many cases of beer I have won with this tip while teaching marksmanship in the Navy for twenty years.
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    perry shooterperry shooter Member Posts: 17,390 ✭
    edited November -1
    I heard my name on this question. think of it this way if the front sight is centered in the rear sight notch left to right with .010 light on each side and you move the front sight so that all the light is on one side between the front and rear sight notch and you have three inches between the front and rear sight the point of impact will change 3 times as much as if you have nine inches between front and rear sight with the same two sight pictures. So a long sight radius does give you better chance of you shot hitting close to the same place EACH time However the longer the sight radius the harder it is to see the relationship between front and rear sight left to right. Can the normal shooter hold a firearm steady with a long barrel that they can align a front and rear sight within.010 Most likely not and this movement is so distracting you can't get your brain to let your finger mash the trigger. go to a gun shop and ask to look at two pistols with same type of sights one long barrel and one short barrel the short barrel gun looks like the sights are locked in place together because you can't see the movement the long barrel sights look like you are shaking because now you can see the movement . the same thing can happen with a rifle take one rifle with vary power scope Look at target with scope on lowest power lay rifle down turn scope to highest power and look at target Best done both ways off hand most people think Damn Now I got the shakes you actually have the same shake low power as the High power sitting
    likewise you can only benefit from long sight radius if you can hold the gun steady if you cant hold steady your brain will run a one question program "should I pull that last thousands of an inch trigger pull [?]now and the two answers to this program "yes and no" will change 1000 time a second. when I was shooting well years ago I had a high Standard pistol with two barrels 5 inch bull barrel and 7&1/2 inch target barrel when the match started I had long barrel mounted if I could see my shake I switched to bull barrel after the first ten shots no shake stayed with long barrel . many people can shoot a tighter group aiming a a plain white piece of paper than one with a target because you can't hit the center of a black target on white paper 10 times in a row because one or more of those ten times you cheated and looked at that black circle and not the relationship between the front and rear sight. Have a good night every one time for one skinny old man to go to bed
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