Arbitrary POI change. Can you help?

Discussion in 'Reloading' started by blancoman, Dec 29, 2006.

  1. blancoman

    blancoman Member

    Messages:
    20
    Joined:
    Dec 27, 2006
    Don't know what forum this belongs in but it's been bugging me for a while now. So, here goes. Steyr rifle shoots 1/2 to 3/4 groups all day long but one day the group is dead center at a hundred. The next day it is still a tight group but now it is two inches left of center. Next range session it is 3 inches low or three inches high. Never seems to be in the same place. I sighted in for a long range hunt before christmas and was printing 1 inch at two hundred. Did not get a chance to shoot that day. Yesterday I shot the rifle and the group was still one inch but now is two inches below the bull at two hundred. What am I doing wrong. I reload and the rounds are from the same batch. what are some causes of this?
     
  2. blygy

    blygy Well-Known Member

    Messages:
    232
    Joined:
    Aug 21, 2006
    First thing I would check would be my scope and mounts. These can sometimes come loose and move around.

    Next make sure the stock hasn't warped @ all and isn't touching the barrel.

    Blygy
     

  3. blancoman

    blancoman Member

    Messages:
    20
    Joined:
    Dec 27, 2006
    That was my first thought also. If the scope or mounts were loose it would not print a tight group. Must be the stock. I can't find any rub marks on the stock and I can run a dollar bill around the barrel all the way down to the receiver so I know that it is free floated. I've been shooting for 35 years and just can't seem to put my head around this issue. Thanks for the help
     
  4. bustayote

    bustayote Member

    Messages:
    7
    Joined:
    Dec 22, 2006
    Are there drastic temp/humidity/air pressure changes between sessions?
     
  5. Brown Dog

    Brown Dog Writers Guild

    Messages:
    635
    Joined:
    Sep 26, 2003
    Rather than equipment, I would suspect that your 'position and hold' from occasion to occasion may be different.

    -different surface under your bipod?
    -leaning into the bipod for 1 group; but not the next?
    -pulling the rifle into your shoulder for 1 group but not the next?
    -differing cheek pressure on the stock etc............

    All the best

    Matt
    /ubbthreads/images/graemlins/smile.gif
     
  6. dbhostler

    dbhostler Well-Known Member

    Messages:
    837
    Joined:
    Sep 12, 2002
    Wood stock?
    db
     
  7. Desert Fox

    Desert Fox Well-Known Member

    Messages:
    439
    Joined:
    Jan 31, 2002
    I seconded Browndog assessment. Your not consistent with the way you hold the rifle or how you approached the scope.
     
  8. Buffalobob

    Buffalobob Writers Guild

    Messages:
    5,085
    Joined:
    Jun 12, 2001
    Check the area of the action for any high point that would cause the action to be torqued when tightened.

    Another way to check this is to take the action out and then put it back in and finger tighten both screws Then tighten them both up some and finally tighten one all the way down and see if that made the other get tight. Next back out the one that you tightened down a turn or so and tighten up the other and see if the loose one is now tight.

    I might not have done a good job of explaining things but basically you are trying to determine if the action is "rocking" back and forth between the two action screws because of a spot in the bedding.
     
  9. blancoman

    blancoman Member

    Messages:
    20
    Joined:
    Dec 27, 2006
    Thanks for the advice. I rather think that it must be me. Shooting off a bench I get different eye relief from shooting off a stoney point or a convienent log or fence post. I tried for consistency this past weekend, funny how a little change makes such a big difference. I noticed that I held consistant but was varying my eye relief. This is probably something you guys already know. If you hold your eye about 5 inches from the scope and slowly move to the proper eye relief, the cross hairs move in relationship to the target. Thanks for the tip. bad shooting technique. Wish I could blame it on the rifle but knew I could not.