Point of impact changing with range (horizontally)

[RayK]

I would guess the scope is not aligned with the barrel (like eeler1 said).

How did you mount your scope?

I put one of these bubble levels on my scope rail.

Mount the gun in a gun vice so the bubble level reads level.

Place a pendulum out in the distance for reference. I use a 5 pound fishing weight attached to a 5/16" rope hung from a tree or similar object.

Align the verticle cross hair with the rope.

Tighten down your scope.

Also make sure your scope rings are aligned with each other. BKL rings are really good that way.

Ray

[DonN]

Hi!

What scope mounts are you using? Also, is there only one mobile jaw on each mount? If yes to question 2, are both mounts clamped on with the mobile jaw on the same side of the rifle? If that's the case and you sighted it in at a particular distance you'd get increasing horizontal shift at greater ranges. Or possibly, the If the mounts have the wrong jaw size then the scope could be horizontally offset from the bore which could cause a similar issue.

Don

[Motorhead]

Yup ... cant errors may be to blame ?

Scott Hull of Morro Bay Airgunners had posted this info on a few sites .... Great synopsis of whats happens with cant errors



Cant errors can be tricky as we try to compensate for them but end up introducing other errors.

I posted this information on another forum after seeing some questions and confusion about cant errors. I thought about putting this in the Optics child board, but scope cant is only one type of cant. Scope cant is not the same as gun cant but the symptoms can be mistaken for each other. I addressed them both in order to show the difference. I had a request from another GTA member to post on this forum. I hope readers here find it useful.

This is some esoteric cant information that I have been thinking about for the past couple of days. There are a number of different cant combinations. How far left or how far right the misses are will depend on the degree of cant, so that could be another subject. The goal is no cant. Hopefully this diagram can help diagnose and solve some of the cant induced errors that I and other readers may experience from time to time. Because of the unique conditions that FT shooters must deal with, we are the ones most likely to be interested in it. Early on in my attempts to shoot airguns with precision, I was convinced that the pellets must be spiraling. Spiraling is certainly a possibility, but from what I know now, it was likely cant errors. In all instances, the gun in the diagrams would be zeroed at the apex of the trajectory.

[oldpro]

I will have to agree sounds like canting to me. Easy fix just go to youtube and find a video that you can understand the best their are lots of them.

[Crusher75060]

what type of targets are those that they are making clean entry holes instead of tearing like the paper ones i use?

You can get nice clean holes by sticking your paper targets to a slice of cardboard. Just FYI

Crusher

[SHOOTINIT]

I always sight in farther, then adjust up/down for the closer distance i'm using, same with a bow

[BlueSteel- 50]

Or scope isn't aligned with the barrel, try 40 yards and see if it shoots a bit further right

Yeah most likely that ~~BS50~~