.

Scope Issues

wynn24wynn24 Member Posts: 103 ✭✭
I have a bushnell banner 6-24x40 on top of a savage lrpv in a .22-250
At a hundred yards it is capable of .310 size 5 shot groups. Here is the problem; It is right on at 100 yards, shoot it at three hundred and it is obviously low but it is also consistintly 6 inches to the right. What in the world is going on?? It will literally consistantly shoot that far to the right everytime.. Any help. Thanks

Comments

  • perry shooterperry shooter Member Posts: 17,390
    edited November -1
    Hello the line of sight thru a scope is a straight line the flight of a bullet is an arc BUT they don't start out at the same place The scope is above the bore line this dictates that you hold the rifle so the scope is vertically directly over the Bore. If you Cant a rifle it will produce left to right error as the range to target changes.[:p][:p][:p]Edit NoNONSENCE Did usA A FAVOR WITH HIS GREAT WEBSIGHT THE HIGHER THE RINGS THE MORE OF A PROBLEM YOU CREATE with cant It you induce left to right error
  • nononsensenononsense Member, Moderator Posts: 10,535 ******
    edited November -1
    wynn24,

    There is a possiblitiy that there is something else wrong with your rifle/scope/you system but the most common by far is cant. Do some testing to see if that's the problem then correct the error. A little written information and a couple of illustrations to go along with perry shooter's explanation.

    http://www.riflescopelevel.com/cant_tests.html

    500300.jpg

    http://www.riflescopelevel.com/cant_errors.html

    500303.jpg

    Best.
  • wynn24wynn24 Member Posts: 103 ✭✭
    edited November -1
    Thanks for the information and the explanation with pics. I havent had time to test this, but i have shot this particular rifle 4-5 different sessions with completely new setups and it produces the same results. I quess what I am saying is I cant believe i am holding the same degree to the right each time. I will however make sure to check this tonight. Thanks again
  • nononsensenononsense Member, Moderator Posts: 10,535 ******
    edited November -1
    wynn24,

    Most of the time it's not you canting the rifle but rather the scope being slightly canted in the rings.

    Best.
  • wynn24wynn24 Member Posts: 103 ✭✭
    edited November -1
    So therefor the results would be the same each time. Dang physics. The web site you provided offered a technique on how to check the scope. I didnt fully understand the procedure. Do you have one that you use, Or should i just let a gunsmith set it up? I guess i have been fortunate to never have run across the before. One thing that I know is different is that the scope rings are higher than I normally use. Thanks again
  • nononsensenononsense Member, Moderator Posts: 10,535 ******
    edited November -1
    wynn24,

    How close is the front lens of the scope to barrel? If you're straining to hold your head and eye in a position to see the reticle, you might want to get a pair of lower rings.

    These are the directions from the website I linked to above:

    "How can you get rid of scope mounting cant error? Well, you can pay a gunsmith lots of money, or you can just mount the scope so the vertical crosshair is level. You can buy tools to help you do this, but there is a very simple way to do it for free.

    Mount your rifle in a vise. Lacking a vise, plop it in some sandbags on a benchrest. Now hang a plumb bob on a ? inch rope about 100 yards away. Adjust the vise and rifle combination so the vertical crosshair is aligned with the string. Does the crosshair line up with the rope? If it wanders off to one side, then the vertical crosshair of your scope is not plumb with the earth. Simply loosen the mounting screw and rotate until the vertical crosshair tracks on the string. Now, install a ScopLevel or SeeLevel in such a manner that the spirit level is level when the crosshairs cover the rope. Or, if your scope isn't that far off (and it doesn't really matter at moderate ranges), just rotate the scope leveling device until it reads level when the vertical crosshair lines up with the rope. That's all there is to it."

    I realize that this website is trying to sell a product but the illustrations are worth linking to.

    Most of us have just screwed the scope onto the rifle and eyeballed things into basic level, then headed to the range to shoot it in on a target using the windage and elevation corrections to get to the aim point. Now at 100 yards you'll be pretty close but stretch your shots out to 200, 300 and maybe even 400 yards and you'll see any tiny error magnified significantly by the distance.

    First count all of the clicks or divisions on both the elevation and the windage on that particular scope. Divide by two and rotate the knobs to that count. You're placing the reticle in the center of the correction range for that scope.

    We have to accomplish two things from the directions, level the rifle and then level the cross hairs (reticle) in the scope to a reference line that is level at a distance. I start in the shop with the rifle in a vise and level. I have 75 linear feet (25 yds) clear to see a set of lines on the wall that are level and plumb. With the scope slightly tight in the rings, I line the reticle up with the lines, rolling it slightly from left to right until the vertical is matched to the lines. Very carefully tighten the scope ring screws, checking for level as you tighten because the scope can roll in the rings as you tighten screws.

    Here's the part that doesn't get mentioned often enough, bore sighting. Without moving the rifle or the scope, take the bolt out of the rifle if you didn't do this earlier. Look down the bore to the lines or target and make sure that the picture you see in the bore is the same as what you see in the scope. If not you need to adjust the scope mount to match the bore picture. If you can't adjust your mounts you will need new rings (or rings and mount) that allow for adjusting left and right or you will have to use your windage adjustment to fix the problem. But this will use up some of the correction you may need at the range for the last corrections. If it's a vertical problem you may have to shim the scope base.

    Now take it out to the range and set up a large target that's level at 100 yards. Set your rifle up on the bench and get it level. Look at the target through both the bore and the scope. If all is well shoot a group and check it out. Your first or cold bore shot may be off slightly so be observant. Warm up the barrel then shoot a group if necessary. Take the target out to 200 yards and check, then 300 yards and check. Make sense?

    It sounds much more complicated than the actual procedure is.

    If you have more questions, ask. If you take this to a gunsmith it can cost a significant amount of money to go through this procedure. Most will bore sight your set up just to get you on paper then leave the rest up to you. The trick is to get the base lined up correctly in the first place then do the rings and make the required corrections.

    Best.
  • wynn24wynn24 Member Posts: 103 ✭✭
    edited November -1
    Again thanks for all your information and advise. I will let you know how it turns out after I get the scope set up correctly.
  • JustCJustC Member, Moderator Posts: 16,035 ******
    edited November -1
    I have used the plum bob (or virtually anything hanging on a string) method. It does work.
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