Why are my shots going to the right?

[RangerBrad]

This first photo is at 200yds so you can see that the scope is sighted in correctly.

the next 2 photos are at 425 and 600 respectivly and were taken while trying to do some trajectory validation (hence high) however there was absolutely no wind at either my location or that of the target.

The center of the 425yd group is 3" right and the 600yd group shows 7" right. I have noticed this for some time so it's nothing that started over night. Any ideas on the cause of this? My first thought was spin drift but this is to much as the 25-06's trajectory shows appx 3151fps.
Speaking of spin drift how do I figure weather my rifeling is right or left as it asks this question on theG7 ballistics program.

I'm looking forward to yals ideas on this as it has me baffeled and I don't know how to correct it. Thank's, Brad

 

[learning]

I would guess your scopes not level. Shoot it at 100 yards then turn your dial up 30 MOA and aim at the same place. Then use a plumb bob to make sure its level.

 

[rscott5028]

most modern firearms sold in the us are right hand twist

but you can run a tight patch through the bore from the breach end and feel direction of the rifling twist

 

[learning]

They are almost all right twist but spin drift won't be that extreme at 425 yards. Scope pry needs leveled. Read about it on Darrel Hollands web sight.

 

[royinidaho]

What learning said in his first post....

 

[RangerBrad]

Learning, I guess I don't understand. Are you saying that if I look at the bullseye at a 100 yd target with the turret at 30moa the vertical will look lopsided? Brad

 

[barnesuser28]

read this. http://www.longrangehunting.com/forums/f5/reticle-perpendicularity-darrell-holland-29352/

 

[RangerBrad]

I watched the man install it and he used levels and I thought he did a good job. I do not have a shooting level on my scope and have never used one before. I notice that it cants on the bipod unless I deliberatly make sure that it's straight (Which I never do). Could it be that I'm simply not holding it level when I shoot? Would it make that much diffrence? Brad

 

[KRP]

You want the scope to track vertically, regardless of level/plumb of the reticle. Put a plumb line on the target and shoot, then adjust elevation and shoot again using same POA. Rotate the scope so it tracks correctly with the ACD.

 

[RMulhern]

Get you some meat wrapping paper or a smooth piece of cardboard about 60" in length and stabilize it against a backstop. Drive a nail at the top of the paper and hang a string from a plumb bob in the center of the paper and use the string to establish you a true vertical line on the paper with an ink pen or black magic marker. Put a small bullseye at the very bottom of the drawn line and from 100 yards or so fire you a shot and see if you are centered up on the small bull. When/if you are centered up....crank the elevation on your scope up to say 25-35 MOA and holding on the small bullseye again....get a good breaking shot and go see where the shot strike is in relation to the vertical line you drew on the paper! Prior to this a requirement is to make certain your scope is not canted on your rifle and there are gadgets available to help you ascertain that the scope is leveled to your rifle! Quite often, depending upon the make of a rifle it's not uncommon to discover that the scope will not be inline with the center-line of the bore and this can cause what you've been experiencing with your shots being off center!

 

[Greyfox]

I watched the man install it and he used levels and I thought he did a good job. I do not have a shooting level on my scope and have never used one before. I notice that it cants on the bipod unless I deliberatly make sure that it's straight (Which I never do). Could it be that I'm simply not holding it level when I shoot? Would it make that much diffrence? Brad

From the targets you are showing, it would appear that your scope is mounted with a cant to the left because your group appears to be moving proportionally further right and higher at as you increase your distance. While its only two targets, your statement that you see this regularly could help confirm this. I think if it was caused by canting the rifle only, inpact points would be more random since it is just as possible to cant left as it is to cant right. The other possible reason for groups to drift in a consistent direction as range increases is an improper rifle hold/cheek weld causing the rifle to angle upon firing. For right handed shooters, this tends to produce hits to the right. I would still recommend a scope level to insure the rifle is not canted, particularly on the uneven ground encountered while hunting, and shooting at longer rangers. It's cheap insurance, and easy to do when you set the plumb on your scope.

 

[Joe King]

I've noticed that too. But it doesn't always happen, it may or may not happen dialing the scope up or using a lower mildot makes no difference. I try to make sure everything is level, my scope is level. But there is one thing that changes, the direction and intensity of the sunlight, I've had mirage cause this at 200yrds too. Maybe it's the glass it's self causes an image shift, not sure. I do know that If I go out 6am and shoot POI is 1/2' right go back out at 7pm it's 1/2" left. The paper target portion of the range faces WNW. If your dialing it in could be your scope isn't tracking strait, you can do a tracking test to check for this though. Don't forget about your body position in relation to the rifle changing every time you move from the rifle. or a gust of wind you didn't notice upsetting you or the bullet at the first portion of the flight.

confirm the things you can change first: scope level, body position, your hold on the rifle, make sure your scope tracks correctly. once you have those sorted out then you'll be able to identify what affect different environmental changes have.

 

[meat head]

I've noticed that too. But it doesn't always happen, it may or may not happen dialing the scope up or using a lower mildot makes no difference. I try to make sure everything is level, my scope is level. But there is one thing that changes, the direction and intensity of the sunlight, I've had mirage cause this at 200yrds too. Maybe it's the glass it's self causes an image shift, not sure. I do know that If I go out 6am and shoot POI is 1/2' right go back out at 7pm it's 1/2" left. The paper target portion of the range faces WNW. If your dialing it in could be your scope isn't tracking strait, you can do a tracking test to check for this though. Don't forget about your body position in relation to the rifle changing every time you move from the rifle. or a gust of wind you didn't notice upsetting you or the bullet at the first portion of the flight.

confirm the things you can change first: scope level, body position, your hold on the rifle, make sure your scope tracks correctly. once you have those sorted out then you'll be able to identify what affect different environmental changes have.

joe
explain how to make sure your scope tracks corectly never heard of it [meat]gun)

 

[Joe King]

the way I do it is. I'll use a target with the 4 bulls 1 in each corner and 1 in the center. I'll start ate the lower left corner and aim only at that target, shoot 1 shot dial in right windage to get to the lower right target shoot 1 shot, dial up elevation to get to the upper right target shoot 1 shot, dial left windage to upper left target shoot 1 shot dial down elevation back to lower left target shot 1 final shot. you should have have a hit on each and the 2 on the lower left should be grouped respective to the grouping you normally get. But you have to aim at the first target you shoot at through out the entire process.