Any thoughts on Groups from a 243.

Discussion in 'Long Range Hunting & Shooting' started by jyenney, Apr 5, 2014.

  1. jyenney

    jyenney Member

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    Hello,
    I have a 243 that shoots .518 (5 shot group) at 100 yards, then I go to 200 yards and the groups go to 4 inches ?
    A little back ground on the rifle. 243, 24" barrel, reloader 22 powder, 95 grain berger vld.
    I was getting 3.5" to 4" groups at 500 yards before I had the action bedded.
    Since it was bedded my original handload would not shoot, so I had to back the load off by 1.5 grains.
    Just trying to get some ideas.

    Thank You
     
  2. WildRose

    WildRose Well-Known Member

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    Something really bad is going on here.

    First I'd say check everything that has threads and make sure they are all tightened properly and torqued to spec. That means scope mounts, rings trigger guard screws etc.

    Next check to make sure the rig is completely free floated?

    What rifle is it? Is it bedded?

    Check all of he above and then shoot a 3 shot group at 100 and then move straight out to 200 and do the same after a reasonable cool down period and see what your results are.
     
  3. Grumulkin

    Grumulkin Well-Known Member

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    1. Just curious; if you were getting 3.5 to 4 inch groups at 500 yards, why did you have the action bedded?

    2. If your gun shoots 0.518 inch 5 shot groups at 100 yards, then your problem is not with the bedding or another gun problem. The problem is with the load. I would say it's probably a velocity issue; i.e., your bullets are too slow and/or the barrel twist is not fast enough for the bullet length at the velocity you're shooting them at.

    Another thing to check would be scope parallax; that is if your scope is adjustable for parallax.
     
  4. Dr. Vette

    Dr. Vette Well-Known Member

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    My thought too. I have one that shot similar groups at 100 and 200, but noted that my crosshairs were moving all over the place at 200 as I moved my head. A change of scopes fixed the problem.
     
  5. d11r529

    d11r529 Well-Known Member

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    I agree with all the replies so far. If none of those solve the problem it is possible that it's a bad bedding job. If you or a buddy have another rifle you could swap stocks with it's an easy way to check if that's the problem
     
  6. jyenney

    jyenney Member

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    Please help me out on that one, Not sure what you mean.( Parallax)

    That is a good question :rolleyes:. That is the first thing I asked myself. I got the action bedded because the stock had a very sloppy fit, and the barrel would not free float. The action is a model 600 and I had to buy a boyds stock. Lets just say my I'm not too patient working with wood, but lesson learned about leaving stuff alone when it works.

    I had a new barrel installed with a 1in9 twist. It only has 150 rounds thru it.
    Not sure about the scope, I have a new vortex pst on my counter. But the trusty Nikon target scope is on there now and has not let me down before.
     
  7. roninflag

    roninflag Well-Known Member

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    what rifle??
     
  8. Grumulkin

    Grumulkin Well-Known Member

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    A 1:9 twist barrel should be fast enough to stabilize the bullets you are shooting.

    You can tell if parallax isn't set appropriately when, if you move your eye a little when looking through the scope, the reticle appears to move to different places on the target. All scopes have parallax set for a certain range; frequently 100 yards. Higher power scopes (usually above 12X) usually have a knob to adjust parallax. When parallax is set appropriately, the reticle will be in focus and, when you move your eye, the reticle will not appear to move to a different place on the target.

    If your pressure is OK, you might try increasing the load a bit.
     
  9. westcliffe01

    westcliffe01 Well-Known Member

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    Seems to be several parts missing in the puzzle
    1) what is the scope magnification range
    2) Does it have an AO or a side focus ?
    3) what rest system is being utilized
    4) What is used as the aiming point on the long distance target ? For that matter what is it on the 100 yd target ?

    Generally, MOST non parallax adjustable scopes are SUPPOSED to be parallax free at 100 yards. That happens to be the most commonly used sighting in distance and the manufacturers may assume that the users are also unlikely to take a shot much further than that.

    I have personally bought a 3-15 Minox scope that was quite expensive and it had no parallax adjustment and it was way off at 100 yards. So much so I got a headache trying to "split" the crosshair shift to even shoot a group. So if one can have that in a $700 scope, it is entirely possible that you may have a significant parallax problem at 400 or 500 yards. To check for it, you need the rifle placed on a firm rest system so it will not move and pointed at a small aiming point at the distance of interest. Now without touching the rifle at all, move your eye left-right and up-down and see where the cross hairs go. If the crosshairs move relative to the target it means that the image plane and the reticle plane are not coincident and therefore when you move your eye position, the reticle moves relative to the target image.

    Parallax can be a big deal, there is basically no limit to how far you could be off (other than the field of view of the scope) if the parallax is off far enough. After my Minox experience I will never again buy a scope that does not allow for parallax to be corrected. The Nikon Monarchs I had prior to the Minox have a side focus and the Vortex PST's I have now have the same.

    The next point is that for target shooting, you should try to use an aiming point of consistent subtention. I use a 1" black circle on a white sheet at 100 yards. At 320 yards, I have a 12x12 white painted steel plate and I spray a black 3" circle on it for an aiming point. So the view of the aiming point is the same in the scope at both ranges. If your eyesight is better than mine and your reticle thinner, you could use a smaller aiming point, but try to keep its size in MOA constant. Otherwise you might have a very hard time seeing the aiming point at 500 yards, or if for example you use no aiming point (hold for the "center" of a plain target) one usually will not shoot as consistent groups.

    If the magnification of the scope is low (I see a LOT of tactical type outfits with a 1-4 or 1.5-6x scope) and they certainly do not help to get the best hold on a tiny target at 500 yards. I myself have a 1.5-4.5 scope that I use for night coyote hunting and my groups at 100 yards suck compared to if I was to use a 16x scope. But this is clearly a compromise between the ability to see the reflection in the eyes of a coyote with a red predator light, and having an acceptable field of view (situational awareness is very important at night in the inky blackness). For any task requiring more range and better accuracy, higher magnification is the way to go. Its not accidental that most of the long range scopes are 20x.

    Often one will use a different rest for 100yd vs 500 yd shooting since in most cases they are not at the same venue. If you are lucky enough to have a 500yd lane at the range where you usually practice, then you are truly blessed. Me, I have to go out to a farm and shoot from a prone position, since there is no suitable shooting station. So I shoot from a bipod, from an unimproved "field" (top of a little hill) and have to pick a spot between the sheep and horse manure...
     
  10. jyenney

    jyenney Member

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    The gun had a model 600 action, and a new factory 24" barrel that I have put 150 rounds thru it.
    The scope is a Nikon monarch 6-18x44 with parallex side focus that I move to the according distance.

    The twist rate is plenty as I have proved the gun out to 600 yards.
    Like I said in my original post, 46 grains of RL22 use to put 5 shots in a dime at 100.
    Now I'm getting .518 groups at 100 yards, but I had to back the load off to 45 grains for it to shoot.
    The only thing that has changed was the action was bedded ?
     
  11. westcliffe01

    westcliffe01 Well-Known Member

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    OK, so the scope does have side focus. But be aware that generally the range values on the parallax adjustment are not correct. You need to verify that parallax has been corrected by seeing if the reticle moves on the target when you move only your eye behind the scope. If that is the case, you need to adjust the side focus until you no longer get any movement of the reticle on the target.

    What about the other questions:
    Target aiming point ?
    Rest/shooting position at both ranges ?

    Was the performance checked after bedding and it still grouped OK ? A bad bedding job can have a negative impact on accuracy. Or perhaps the grouping was just checked off a bench and not from a field position ?
     
  12. gohring3006

    gohring3006 Well-Known Member

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    if the only thing that has changed is the bedding and you were shooting .5 groups before than your action is stressed somewhere in the bedding the stock needs either checked and relieved or replaced
     
  13. WildRose

    WildRose Well-Known Member

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    Did you not also change scopes?
     
  14. jyenney

    jyenney Member

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    I will put the new vortex on today.

    gohring3006- I think your on to something with the stock, the only thing I can think of is it is still shooting decent groups at 100 yards (last group yesterday was .529), not as good as it was, but not too bad for a factory barrel. Shot at 200 again and the group was 4 ".

    The stock is a wood stock, maybe I have the screws too tight. I read somewhere that you should put the butt of the stock on the ground, put plenty of downward pressure on the barrel and tighten the front screw very very snug, then tighten the back screw tight.
    is this correct ?

    The rest is on a concrete bench with bipods and sand bags.