vertical stringing of shots?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by REV, May 11, 2005.

  1. REV

    REV Active Member

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    I went to the range yesterday and shot 3 five shot groups at 200 yds. the shots measured less than .5 inches left to right but 6 freaking inches top to bottom, any ideas? BTW it is a Savage bull barrel .223 topped with a Simmons 6.5-20x44. Has a history of shooting under .5 inches @200. Harris bipod in front and sandbags in the rear. Black hills match hollow point (68-69 grains).
     
  2. Guest

    Guest Guest

    Verticle stringing? Different or non-uniform powder charges, different primers, Norma brass, (had to say it) mix of brass, parallax adjustment, poor quality / fatigued scope, loose receiver screws or scope mounts, wind. Did I miss anything?
     

  3. heatseekins

    heatseekins Well-Known Member

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    How hot is your load? I have found that often to tune out vertical you need to go up in powder charge, but If you’re already at max pressure try going down or switch powder. There are usually a couple of different powder charges your barrel will like. My 308 shoots its best groups with either 39gr or 44gr of varget.

    Glen
     
  4. bucknutz

    bucknutz Well-Known Member

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    simmons scope? /ubbthreads/images/graemlins/frown.gif when i shot a bi-pod alot my groups were always up-down especially on a flexible truck hood. is it jumping? /ubbthreads/images/graemlins/blush.gif or hard to soft pressure with your hand?
     
  5. Buffalobob

    Buffalobob Writers Guild

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    Does it have a history of 0.5MOA with bipods? May not like bipods

    Here are some simple things most of which I imagine you have already done

    1. Check the action screws

    2. Check for barrel contact with the fore end or near contact

    3. Take action off the stock and look for strange objects that would interfere with a solid bedding


    4. Look at fired brass primers for signs of erratic pressure – some very flat and some normal. If so then perhaps you need to go to item 5 or perhaps you got a bad lot of ammo. Are the indentations normal- no broken firing pin.

    5. Take a cleaning rod and run a very oily patch down the barrel to get it slick. Put a good brush on the cleaning rod that fills the barrel well and turns with the rifling. Run the brush through the barrel until it is sticking out of the muzzle. With your thumb and one finger grasp the cleaning rod (not the handle but the rod itself) and slowly and gently and with even pressure pull it back through the bore. If at about six inches from the chamber the brush begins to drag and you can hear a rasping sound and you have to exert more pull with your thumb and finger and it feels like you are pulling it through the grand canyon then you have the plague. Hard carbon fouling. This is a build up of powder fouling that has had bullets squeezed through it until it has compressed to a hardness that rivals diamonds. Under regular cleaning you will get the great majority of the bore clean but the area in front of the chamber will resist and your patches may seem to come out clean but over a period of time the situation grwos worse. At this point in time you are in for a bad time and need to be careful not to ruin what seems to be a good shooting barrel. If this is the problem you should come back and ask about hard carbon fouling. Most people seem to worry about copper. My experience the carbon is worse.
     
  6. REV

    REV Active Member

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    Thanks for all the suggestions. Everything, scope, ammo, bipod are all the same, the ammo is even from the same box as a group just over 1/4" @100. I will have a look and post results, thanks!
     
  7. Lee in OH

    Lee in OH Well-Known Member

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    I agree with heatseekins. I've found that vertical strings mean just a tad more powder and you're there. It usually holds true, but not every time.
     
  8. Mysticplayer

    Mysticplayer Writers Guild

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    Try shooting with a proper pedestal front rest and rear sand bags. If you are shooting off a solid bench (concrete), a bipod can bounce.

    Voila, stringing. 100yds is too close for most tuning problems to show up. That is why I have always suggest shooting further while testing.

    If using BH match ammo, I will give it the benefit that its well loaded and consistent. So look at the rifle as the main culprit.

    Are you using the factory plastic stock? If so, you must bed it (you actually can with the right bedding compounds and prep) and free float that barrel. You will need a BIG gap.

    With the better front rest and bedding, should solve your problem. Assumed that scope and mounts are ok. Check scope bases, they do loosen.

    Jerry
     
  9. HoytemanPA

    HoytemanPA Well-Known Member

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    My vote goes for the scope being FUBAR. Shoot a five shot back at 100, if vertical there, I'd change the scope.
     
  10. johnnyk

    johnnyk Well-Known Member

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    I have the same rifle....I think (Savage 110FP/.223?). I noticed problems with the bull barrel making contact with the Tuperware stock, sometimes. I stopped using the bipod on mine and it settled down. Still needs bedding or handle change though. Johnny K.