oldrookie

This question is for all the range rats out there. I was at the range last night tweaking my hunting load. The first 5 rounds were a couple inches high and inch and a half left of the bull. The group itself was good (by my standards). I adjusted the scope down 6 clicks. The next 5 rounds grouped well but were a inch high and about inch and a half to the right.

The only adjustment to the scope was high/low. Why would this make a difference in the grouping from left to right? By the way, the distance was 100 yards and the load was 245g, 100g 777 pellets and 777 primer.

gleason.chapman

That is just variation about a "mean" or central tendacy of your shot. It is human to be consistently inconsistent. I use a Black and Decker work bench and put a cloth to hold my gun in it, and I still have variation at 100 yards. It doen't sound to me that you scope clicks are accuate.
Chap

nchawkeye

I have seen certain scopes do this...My buddy has a Simmons Aetec that consistantly does this type of thing...Move it left or right and the elevation also moves, move it up or down and the horizontal moves...He has another Simmons that moves after the shot, I've tried tapping lighty with a screwdriver handle to help it "settle" but it still waits until you shoot it to do so....

oldrookie

Thanks guys. I'll see if the tapping works. All I was trying to do was bring it down a little at a time. It did drop around an inch but when the total group moved from the left side to the right side, I was totally confused.

The scope is not high end by any means. Nikcon prostaff 3x9. Is there any way to make sure the adjustment to the scope stays tight inside the turret?

nchawkeye

I don't think that they are moving inside the turret...But you can try shooting a square...It will take some time with a ml, so I probably wouldn't try it, btw I have had guys have good luck with the Prostaff...To check how a scope is tracking, here is what you do....

1...Zero the gun...say, dead on at 100...

2...Move both horizontal and vertical adjustments....Say 8 clicks up and 8 clicks right (this should move the group 2 inches up and 2 inches right, if the scope adjustments are 1/4 inch per click at 100)...Then shoot 3 shots....

3...Go 16 clicks Left...Leave the horizontal alone....This should put you 2 inches high and 2 inches left of your original zero...Shoot 3 shots....

4...Go 16 clicks Down....This should put you 2 inches low and 2 inches left of your original zero....Shoot 3 shots...

5...Go 16 clicks Right...This should put you 2 inches low and 2 inches right of your original zero....Shoot 3 shots....

6...Go 8 clicks Left and 8 Clicks Up....You should be back at your original setting or sighted back in at 100 yards....Shoot 3 shots....

This is called "shooting a square"....You should have 6 shots in the middle and 3 shots each in each corner of the square...Make sense???

As I mentioned...I wouldn't worry about doing all this with a muzzleloader...Just get her dialed in....I would check it a time or two before the season to make sure she stays put...If the scope still acts funny, I would put another on this gun and shoot a square with a center fire (or even a good .22) to check its tracking....

nchawkeye

btw...Be sure to check the scope mounting screws...Its embarrassing when simple solutions are the key to a problem like this....

Don't ask me how I know!!!!!

cayugad

nchawkeye took the right approach there, check the mounting screws on the base and the scope rings.Like him, I will not mention why this is important...

As for why it would move like that, I have seen the same thing with a Bushnell I had. I called them, and asked them what was going on. They asked I send it back and when it was returned, I would not swear to it, but I am still under the impression they gave me a new scope for the old one. Their note said, they could find no problem. I remounted it and they were right, there was no problem. What they did, I have no idea.

dmurphy317

One other possibility is if the scope is not quite vertical in the mount or in your hold. In other words, if the scope is mounted with the crosshairs slightly tilted the adjustments will move in both axis as an adjustment is made due to the angle. This can also happen if the gun is not held exactly vertical when shot. I have noticed similar errors on paper when my target frame was slightly leaning and I lined up the vertical cross hairwith the target and caused a non vertical alignment of the gun and scope. If you lean to the left or rightthe shot will not hit where you are aiming. This can also happen when shooting on a hill or other unlevel ground due to our tendency to want theigs to line up, kind of an optical illusion that makes you think it is not level. This is why many target shooters use a level mounted on the gun that can be seen when looking through the sights.

oldrookie

David, I appreciate the suggestion. I thought about that after I posted. I use somewhat of a cheap bench rest and sometime fight the rest pinching the gun as I am aiming and feal like I am slanted to the right. I'll notice it release the hammer and reset it in the rest.

Your saying if your slanting one way or another it will nock the scope out of wack accordingly? I will be back at the range tomorrow. I'll shoot off of a front bag....at least I will know I am verticle and horizonal. Thanks!

Hopefully its not the scope.

dmurphy317

It's not actually knocking the scope out of wack, just shifting thePoint Of Impactfrom the Point Of Aim. The bullet is affected by gravity in a vertical direction. When you tilt the gun, your line of departure for the bullet is changedbased on theamount and direction of tilt.When you tilt, the barrel will be pointingto a different vertical plane from your scope dueto the angle difference between the line of sight and the line of departure (line of bore). Gravity will act on the bullet and it will end up shooting to a differentPOI than the POA. Distance and degree of tilt will determine how much difference it will be. It's been a while but I seem to remember that if you tilt right the POI will shift the the right.