Level with angle finder.

I got this yesterday. I was looking just for a level but couldn't find any that got decent ratings that was also inexpensive. I ran across this that has an angle finder too. The angle finder is marked in 5 degrees and IMO is readable within 2.5 degrees and has a screw adjustment. The level swings out and has spring loaded ball detent to hold it in position. It has a nice feel to it. It seems to work pretty well for air gun use. I can hear some noises from angle finder when I move it around and the hinge for the level may loosen up under repeated high recoil. so I'm not sure how it would hold up to a PB like a 338 Lapua or 50 BMG.

The only downside is cost and added weight to the gun.

https://www.amazon.com/gp/product/B0774QHY4G/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

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The higher your scope is off the bore axis and the further the target distance the more import it is to keep the scope aligned vertically to the bore. If you don't do that your point of aim will seem to move left or right and the elevation will be less than expected. I know David Tubb will disagree, but he is shooting fixed known distances with known corrections.

The angle finder is to adjust for shots at targets not perfectly at the same elevation as the bore. The 1st order correction would be to use the strait line distance to the target times the cosine of the angle. For smaller angles the difference is about zero and can be ignored.