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vertical stringing

Discussion in 'Handloading and Reloading' started by lordgroom, Oct 22, 2008.

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  1. lordgroom

    lordgroom Member

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    Could someone please explain vertical stringing and what causes it? I have seen it referenced in posts and in articles I was reading from a accuracy magazine I was recently reading.
     
  2. USSR

    USSR Member

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    It's when the dispersion of your shots is primarily up and down. For example, in a 10 shot group, if the spacing of your two widest shots on a horizontal plane are 4", while the spacing of your two widest shots on a vertical plane are 10", that is indicative of vertical stringing.

    Don
     
  3. tbtrout

    tbtrout Member

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    Breathing will cause vertical stringing.
     
  4. Walkalong

    Walkalong Moderator

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    Poor shoulder control (inconsistent) will cause vertical stringing. Really bad ES's will cause it at longer range.
     
  5. NuJudge

    NuJudge Member

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    Failure to maintain the same focus on the front sight and sight picture with respect to the target will cause it also.
     
  6. everallm

    everallm Member

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    Poor breath control is a regular culprit as well as, at long range, inconsistent powder throw in hand loads.
     
  7. lordgroom

    lordgroom Member

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    Seems like most of the culprit is in shooting technique, rather than handloading mistakes.

    I have a 3 shot group which is a tight 0.6". They are .223 55gr fmjbt fired from an AR at 100 yds (I believe I can still improve this by modifying seating depth). The holes are basically touching but in a vetical line. Is this vertical stringing? Or does there have to be some spread for vertical stringing?
     
  8. NCsmitty

    NCsmitty Member

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    Vertical stringing with a bolt action especially, quite often occurs as the barrel heats from repeated shots. Often if a barrel has contact with the forward portion of the stock, the heating will cause the shots to rise progressively.
    I float all my bolt rifle barrels.

    NCsmitty
     
  9. The Bushmaster

    The Bushmaster Member

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    My Browning A-bolt barrel has been floated and I have a vertical stringing spread of three shot 1 5/8" at 200 yards. Guess it's my breathing...
     
  10. swampshooter

    swampshooter Member

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    A single 3-shot group tells you NOTHING.
     
  11. The Bushmaster

    The Bushmaster Member

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    L O L...:D Guess I should have put a "big Grin" smilely on that one...
     
  12. rcmodel

    rcmodel Member in memoriam

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    How dare you shoot three-shot groups! :cuss:

    Don't you know that anything less then 20 10-shot groups is statistically insignificant!

    If you don't burn out a barrel during load development, you just aren't going to be statistically significant! :D

    rcmodel
     
  13. lordgroom

    lordgroom Member

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    I agree. If I can't produce a clinically significant sample every time I fire I should just keep the guns locked away and not even bother to go to the range???????

    come one guys

    Life dictates that sometimes you do things in a less than ideal manner. At that point in time I had a time limit.

    I understand that none of you like 3 shot strings but this question was designed to help me learn something about vertical stringing, not 3 shot, 5 shot, 10 shot, 20 shot, or 100 shot groups.

    By the way. To the question of statistical significance, a power analysis dictates that you will need far more than 10 shots per powder weight change if you select 4 different powder weights.
     
  14. EShell

    EShell Member

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  15. The Bushmaster

    The Bushmaster Member

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    I don't know swampshooter. When I add them all together (several 3 shot strings[groups]) they tell ME a lot...:scrutiny:

    Yes...I know...rcmodel...I did a cardinal sin...:D
     
  16. Walkalong

    Walkalong Moderator

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    It can show potential, that is for sure. If you get real serious, you can jump up to 5 shot groups.

    For a hunting rifle 5 shot groups are overkill by 3 shots, maybe 4.

    If your hunting rifle will shoot a good 3 shot group over and over, you've got a good one.

    There is no reason not to let the barrel cool between shots either, unless your testing a target rifle that may have to shoot a lot of shots in a hurry.
     
  17. possum

    possum Member

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    alot of times when i am coaching soliders an people in general i see the "stringing" when they change thier point of aim from shot to shot. i hope that we are discribing the same thing here but i think we are.
     
  18. Ky Larry

    Ky Larry Member

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    As was stated above, vertical stringing can be caused by the barrel heating and making contact with the stock. Itcan also occur in a rifle that has a freefloated barrel. I had a Ruger 77 in .243. I freefloated the barrel but after 5 shots the barrel was making contact with the stock. A gunsmith told me this was caused by stress in the barrel due to uneven heat treating and tempering. The answer was to let the barrel cool after 4 shots and the stringing problem went away.
     
  19. uk roe hunter

    uk roe hunter Member

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    this problem may also be due to the stock bolts not being tight enough. the rifle action must be pulled down and bedded properly. I agree with the barrel floating theory. my rifle barrels all float except my model 7.
     
  20. Slamfire

    Slamfire Member

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    With my NRA "service rifles", I can clearly see vertical stringing in the prone position.

    As your face slide up and down the stock, the point of impact on paper goes up and down. I think it goes, move up, the point of impact moves up.

    People do not want to acknowledge that the greatest error source is the shooter, and the greatest source of shooter error is inconsistant position. Call it a poor "stock weld".

    I saw this today shooting standing with my M1a. As I moved closer to the sight I had to add elevation. I shot a 95-2x standing. That was my best string, my position stunk today.

    You notice vertical stringing when your groups go up and down, but not sideways. With a target rifle, it is easy to figure out that the cause is poor position.

    When I have rifles that vertically strung, in all but one case, it has always been due to poor bedding. Seldom will poor bedding only show up in vertical stringing, you will also have variations side to side, but I think the biggest deviation is vertical.

    I have one Ruger #1 in 30-06. It vertically strings everything in a perfect line. The line is about 2" high. I have played around with tension screws, free floating, pressure bedding. The thing vertically strings.
     
  21. snuffy

    snuffy Member

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    Well here's a different answer for you. Vertical string CAN be caused by using the wrong powder. Or a powder with the wrong burning rate for the cartridge being loaded.

    I saw it happen once with my 7 X 30 Waters contender. I experimented with 4198 powder, even though there were no loads in any of the manuals for it. I understood exactly why that was, it is not suited for that cartridge! The group was a long, straight line of holes, like rungs on a ladder. 4895 turned out to be THE one powder that produced excellent round groups in that pistol.
     
  22. ~z

    ~z Member

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    Snuffy, you are right on! Not that anyone else is wrong. If stock weld is good (and we are talking bedded bolt rifles) I have noticed powder as the culpret, either poor choice or poor volume. I have found vert stringing to occour right around the "sweet spot" in load development, either a few tenths more or less powder will bring em back to round.
    ~z
     
  23. Coltdriver

    Coltdriver Member

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    I shoot a Ruger #3 and a couple of Encore barrels.

    By letting the brass stretch between the shoulder and the base and subsequently eliminating any headspace my single shots will vertically string reliably.

    I was trimming the brass (necks) to the right case oal but not paying attention to the shoulder to base dimension. After I bumped the shoulder back I got the best shooting from the number 3 that I have ever experienced and my Encore barrels became more predictable.
     
  24. snuffy

    snuffy Member

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    I didn't mean to imply the other answers were wrong, they ALL could certainly cause vertical stringing. I simply wanted to add the powder choice to the equation.

    Very interesting! I will keep that in mind when sizing for my contenders!
     
  25. NC-Mike

    NC-Mike Member

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    Get a Mini-14 and you will learn all you want about vertical stringing... :evil:
     
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