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Thread: serious moa question

  1. #1
    dog chaser distant stalker's Avatar
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    serious moa question

    We had a bit of fun in the other thread about consistant accuracy. A few snickers bars got handed around and all had a bit of a laugh but now i have a serious question. I have noticed while tuning loads that some pills seem to "go to sleep" further out. I see it more with high bc pills where group size at 200 or 300m can be the same size or smaller than that at 100. I have some theories on why that may be the case but am curious as to who else has found the same and if there has been proven theory about why it happens

  2. #2
    By Popular Demand gimp's Avatar
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    Bryan Litz disagrees with the theory of "going to sleep" and so do I.


    It doesn't make sense that the rate of dispersion would decrease with range.

    In image form, it would look like this:

    Name:  dispersion.jpg
Views: 527
Size:  8.1 KB


    More likely insufficient data to draw conclusions, psychological factors with the shooter, etc. I think Litz mentions it in one of his books? He also posted about it a lot of snipershide somewhere back in about 2009

  3. #3
    dog chaser distant stalker's Avatar
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    Nice. Youve touched on my "theories" was looking for something from the likes of litz. Will look where you have mentioned. All the discussions ive seen on it have been "interesting" with not a lot behind them

  4. #4
    AB Precision
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    See I have a 7mm I own that will struggle to put 5 shots on a a4 page at 100m take the same rifle same load to 200m of more an it shrinks a lot it would hit that a4 page better at 1000m then 100m

  5. #5
    By Popular Demand gimp's Avatar
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    I'd look it up in his book but I don't have them with me. I'll try find the thread on Snipershide, unfortunately they've changed their software since then and the search and old threads are fucked

  6. #6
    By Popular Demand gimp's Avatar
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    Quote Originally Posted by tui_man2 View Post
    See I have a 7mm I own that will struggle to put 5 shots on a a4 page at 100m take the same rifle same load to 200m of more an it shrinks a lot it would hit that a4 page better at 1000m then 100m


    And if you stop and think about it, how can it possibly do that from a physical standpoint?? How can the rate of angular dispersion decrease? It's like shooting a 5 shot group by throwing 5 curveballs that all curve out in different directions then back in again to the same point. There's nothing to make a bullet "going to sleep" actually point back inwards in relation to flight after flying off erratically due to poor stability.

  7. #7
    Member BRADS's Avatar
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    serious moa question

    Quote Originally Posted by tui_man2 View Post
    See I have a 7mm I own that will struggle to put 5 shots on a a4 page at 100m take the same rifle same load to 200m of more an it shrinks a lot it would hit that a4 page better at 1000m then 100m
    Bullet instability? What courses this?
    I've also seen a rifle shoot 2moa+ at 100 and yet still hit fist sized rocks at 1000 yards


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  8. #8
    By Popular Demand gimp's Avatar
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    This pretty much covers the "going to sleep" myth

    Epicyclic Swerve


    It doesn't cover alternative possible explanations for why you may see smaller angular groups at longer range but I'd guess a combination of not enough shots or precise enough measurements to draw any real conclusions, errors combining to cause smaller groups at long range on occasion, and psychological issues with the shooter (can't see the holes, not stressing about ~*sub moa groups*~, doesn't get all tense and tunnel vision on the target and fuck it up)

  9. #9
    AB Precision
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    Quote Originally Posted by gimp View Post
    And if you stop and think about it, how can it possibly do that from a physical standpoint?? How can the rate of angular dispersion decrease? It's like shooting a 5 shot group by throwing 5 curveballs that all curve out in different directions then back in again to the same point. There's nothing to make a bullet "going to sleep" actually point back inwards in relation to flight after flying off erratically due to poor stability.
    I have no idea how it comes right after been so bad at 100, all I know is it does from one end to the other, start crap stay crap it how it should be but starts crap goes mint, its my go to LR hunting rifle just sigh in etc all down 250m same as when I done the load for it, to get around how poos it was.

    Its 1.8" twist pushing 180s hard should be stable as

  10. #10
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    A projectile doesn't only spin but it yawls as well so maybe the yawl spot is better on the target at the longer range than closer? With BP shooting you can alter the horizontal hit on a target by playing with the amount of BP in the load, and not adjust thing the sights, and active tighter grouping,
    R93 likes this.
    Boom, cough,cough,cough

  11. #11
    Member kimjon's Avatar
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    I've noticed this too with one of my rifles. It shoots about MOA at best (100y) when zeroing...but at 525y where I leave my steel plate set up, it often prints 0.5MOA groups on the gong.

    I've just put it down to phycology, i.e. the rifle is a real hard kicker with no suppressor or brake fitted and I'm a tad recoil sensitive, so most likely I jerk the trigger in anticipation of getting booted by it. But at long range I seam to relax a lot more - not as much as hunting where you never feel the shot, but close to it...and that why I think my shooting sometime improves?

    But my shooting is so poor at times its hard to draw serious conclusions from it as one day I think I could win the Olympics...the next I couldn't hit water if I fell out of a boat!
    kj
    distant stalker and Maca49 like this.

  12. #12
    Almost literate. veitnamcam's Avatar
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    I tend to shoot better groups a 200 than 100 but in my case i think it is my eyes. After a few shots i seem to get tired eyes and on high mag at 100 find either the target or the crosshair is sharp but not both. I have tried playing around with the parralax and diaopter and it makes no difference. But i don't seem to have this problem at 200 or further or at least not to the point it is distracting.

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  13. #13
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    I guess the only way to really prove if anythings happening is by setting up paper at 1 2 and 300. Aiming at the 100 and "shooting through" the other 2 targets.
    distant stalker and steven like this.

  14. #14
    By Popular Demand gimp's Avatar
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    Quote Originally Posted by Towely View Post
    I guess the only way to really prove if anythings happening is by setting up paper at 1 2 and 300. Aiming at the 100 and "shooting through" the other 2 targets.

    Yes, and I would put a lot of money on, if this were done, the results being fairly consistent in angular terms

  15. #15
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    I just don't trust my shooting at a hundred yards. I zero close enough at 100 and then back to 400 or 500 yards where I shoot so much better.

    Nothing to do the rifle. I think the problem is seeing to much and overthinking it at 100. Maybe its like the old peep sights...the brain just naturally centres the foresight and on a target at 500 with limited magnification I get the same effect.
    veitnamcam likes this.

 

 

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