1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

13 yard poi Neil Winston

Discussion in 'Shooting Related Threads' started by 46_trap, Apr 6, 2009.

Thread Status:
Not open for further replies.
  1. 46_trap

    46_trap TS Member

    Joined:
    Jan 29, 1998
    Messages:
    78
    Neil Winston or any trapshooter that wants to jump in,
    I know how to construct the pattern board and have made a search of TS.com, but have not found the info that I want.
    Lets say that I have a bulls eye and a cross in the middle.
    If I am shooting 1,2, or three inchs high at 13 yards, how high is that at 32 and 40 yards.
    One inch high at 13 yards = ? at 32 yards and ? 40 yards
    I thank you



    Ed Keefer
     
  2. mollyone

    mollyone TS Member

    Joined:
    Jan 6, 2009
    Messages:
    299
    Go to search type in 13yds will get all info
     
  3. maltzahn

    maltzahn Active Member

    Joined:
    Jan 29, 1998
    Messages:
    542
    Location:
    Creston, IA
    Not considering any gravity shot drop. 2 " high at 13 -- 2"x 3 = 6" high at 39 yards.

    Maltzie
     
  4. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    Ed - a simple way is to just use 2" high at 13 yds is 6" high at 40 yards. This is close enough. You can get more accurate bu including the negative effect of gravity and the positive effect of the sight/center of the bore. If you want intermediate yardages between 13 and 40, and you are 2" high at 13, then just multiply the yards to the target by 0.154. At 22 yards, it would be about 3.4 inches high.

    Pat Ireland
     
  5. JerryP

    JerryP Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,753
    goose2 , short answer is yes.
     
  6. GunDr

    GunDr Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,913
    At what distance are you determining the 70/30? At 40yds, 2" is just short of a 60/40 pattern. A 70/30 POI is 6" high at 40yds.

    You really cannot use the percentage POI in any other yardage but 40yds, in determining the POI of a trap gun. With any distance shorter, you should just measure from your aiming point to the center of the pattern.
     
  7. JerryP

    JerryP Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,753
    I assumed the goose meant 2 in at 13yd.
     
  8. JBrooks

    JBrooks TS Member

    Joined:
    Nov 6, 2006
    Messages:
    3,707
    You can't use a %/% POI conversion unless you know how big is the kill zone of your pattern at a given yardage.

    By example, if you had a kill zone of 24 inches at 39 yards and your POA was at 6 o'clock of the pattern's POI, then you would need to be about 4 inchs high at 13 yards. 3 x 4 equals 12 inches which is half your 24 inch pattern.

    This would place 100% of your pattern above your POA at 39 yards.

    If you POA was in the center of your pattern so that half was above and half below, you would be at 50/50.
     
  9. BigM-Perazzi

    BigM-Perazzi Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    8,542
    Location:
    HELL, MICHIGAN
    It's a ratio, do what Pat says.
     
  10. zzt

    zzt Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    3,462
    Location:
    SE PA
    Ed, One inch high at 13 yards = ? at 32 yards and ?

    32/13=2.46*1"=2.46" high at 32 yards.

    40/13=3.08*1"=3.08" high at 40 yards.

    Forget gravity and everything else. This will be accurate to within 1/2" for your flat shooting gun.
     
  11. 46_trap

    46_trap TS Member

    Joined:
    Jan 29, 1998
    Messages:
    78
    Thank all of you. I think that Pat Irland explained it best.What I was looking for and had a hard time explaning was: I put a big cross on target paper and make a bullseye at the center. I have different shooter that will put the front bead at the bottom of the bullseye. Then shoots,he is six inchs high.But he shoots fast and usually hits the target at about 32 yards (Sometimes) I want to tell hime how high his shot should be on the target paper, to get a good pattern at 32 yards. So if he is shooting 2 inchs high at 13 yards, the he will be shooting 4.929 yards ate 32 yards (lets round that out to 5 inchs.)Do I have that right?


    Ed Keefer
     
  12. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    Ed- My first explanation above was the simplest and reasonably accurate. The best calculations can be more complex and more fun. These would include gravity fall of the shot (non linear due to deceleration of shot) and the distance from the front sight to the center of the bore (linear increase). This method will give about the same results as obtained in my first simple example.

    It is important to realize that determining the POI from a rest only measures where the gun shoots. Where a shooter shoots the gun brings in another factor. The angle between the shooters eye and the front sight. A single gun can shoot very different for different shooters. A shooter can make one gun shoot very differently simply by changing his head position.

    I believe every shooter should test his gun at 13 yards from a rest to make sure it is not shooting to the right or left. Test at least 5 shots.

    Pat Ireland
     
  13. JB Logan Co. Ohio

    JB Logan Co. Ohio TS Member

    Joined:
    Jan 29, 1998
    Messages:
    1,327
    Oh man, too much math so early in the morning....

    JB=Jerry Beach 8503917
     
  14. JBrooks

    JBrooks TS Member

    Joined:
    Nov 6, 2006
    Messages:
    3,707
    Pat is right about how a shooter actually shoots a gun. That is why I prefer starting below the mark and bringing the gun up until I see the mark how I like to see a straight away target and then firing. This will give you a little more information on where you shoot the gun.
     
  15. Neil Winston

    Neil Winston Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,848
    For all you OC types, here's the layout, though zzt's math is easier and works fine for many guns and most reasonable POI's.

    1. Take the distance from the top of the bead to the centerline of the bore, call it 3/4 inch.

    2. Add the amount the shot dropped on the way to the 13-yard pattern, call it 1/4 inch.

    That means to get to, say, one inch high, without gravity, it would have risen two vertical inches. That the sum of how far it started below the Point of Aim, the amount it rose, and the the amount it "fell."

    It will rise three times that (again without gravity) on its way to 39 yards, call it 40 to the accuracy needed. Remember, that "three-times" is based on where it started, 3/4 inch low. (Edited for clarity at noon.)

    That means without gravity it would have hit six inches above the start but adding in gravity's 13-to 40 yard effect of a fall of two-and-a-half more inches (at least) you end up with a downrange POI of something over 3 inches high, still relative to where it started, which results in a pattern center about two-plus , maybe three inches over the Point of Aim at that distance. (Also edited for clarity at noon.)

    If it's an underbarrel of an O/U, an unsingle, or has a high rib (say a TMX, DB81, or one of those "new models," it'll be higher than that.

    But the usefulness of the "at the target" POI calculated to this precision or just the 3x shortcut is limited, since I've never been able to use it for anything. What is it for, anyway?

    Neil
     
  16. John Browning

    John Browning TS Member

    Joined:
    Jan 29, 1998
    Messages:
    181
    Pat, I still cannot understand why you want to use a rest to test for left or right at 13 yards. I test by moving my shotgun up to the spot on the paper. This is how we shoot targets, doesn't it make sense to check for right and left the same way.
    I also have thought about setting my poi slightly off center, I seem to shoot ahead of some angles and behind others. John Moore
     
  17. GunDr

    GunDr Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,913
    John,

    By shooting from a rest, you are trying to determine where the GUN shoots, not where YOU shoot it.

    It's possible 12 different shooters; shooting free-hand, to shoot 12 different POIs, but if all 12 were to shoot with the same sight picture, from the same distance, from a rest, theoretically, the POI should be the same for all.

    Doug
     
  18. phirel

    phirel TS Member

    Joined:
    Jan 29, 1998
    Messages:
    9,556
    John- Another reason I use a rest and shoot 10 rounds at 13 yards is, that even with a rest and a release trigger, I will pull off one or two rounds to the right or left. If I shoot 10 rounds, eight are centered three inches high and two targets are two inches high and two inches to the right, I realize that I pulled off tow of the test rounds.

    If I want to test a load in a rifle, I use a rest. I would never test a load shooting freehand. I test my shotgun the same way I would test a rifle.

    Pat Ireland
     
Thread Status:
Not open for further replies.
Search tags for this page
neil winston 13 yards
,

neil winston 13 yards poi

,
neil winston poi