Scope leveling question

Curious to see if when mounting a scope on a rifle y'all level it to the gun, or level it to your line of sight.

From what I've read all the experts say level it the gun, but to me that would assume a person's shooting style holds the gun perfectly vertical. Conversely if it's canted to the gun it may be perfectly level to the shooter.

Level to the gun. That way when adjusting for poi it will adjust true. If using hash marks will be true.

I level to the rifle, and keep level during shooting. There's an old debate that the scope only needs to be level during shooting but I do not subscribe to that. Sight offset has to matter.

Always to the gun. If not the POI will only be correct at one exact distance. Any other distance will impact left or right from the POA. If it is not square to you after squaring it to the gun then you need to adjust your hold on the rifle until you retrain your hold.

Now, with that said, if you’re talking about hunting at normal distances and not target shooting or extended range (200+) then it’s irrelevant. Do as you wish.

Always to the gun, unless all shots will be at whatever distance you sight in at.

You need your elevation turret to adjust identical to the offset from your scope/bore axis line. So if you don't align to the gun, you will have an unintended offset at non-sighted distances.

I had a scope recently that was just a hair mis-aligned. Just barely enough for me to tell when I leveled the scope to the gun. I ended up running a tracking test and found that it had just a hair over 1 degree of error. Sounds like it would be in tolerance and not a big deal...right? Wrong - it translated to .4 mils of error over 14 mils of travel, which is enough to take you completely off Jason's half MOA and 3/4 MOA plates at 800 yards with a 6.5CM, and almost off the 1 MOA plate. That's way past unacceptable to me.

Anyway, all that to say - scope alignment is critical and is probably the thing I spend the most time on when mounting/sighting in. The other thing I spend a ton of time on is diopter adjustment, but I'll save that speech for another thread.

Guys I appreciate the feedback. This has been very insightful.

One other thing though: when mounting a scope do y’all use a target to reference the level? In other words do you look through the scope and line it up with a target, or do y’all use an actual level resting on top of the scope itself?

I level the reticle with a known level object. At home DIY option is a 1/2" rope with a heavy weight, that's just an overgrown plumbob.

With my rifle is a cradle, leveled & lined-up, I vertically align the scope's crosshair by viewing through my shop door at the neighbor's door frame that is about 200 yds away. The small pot plant on his porch is also helpful for bore-sighting after everything is tightened down.

BTW: My neighbor's house is a vacation home & I do this when nobody is around.

years ago I always used a telephone pole 100 yards down the street and the insulator on the top was good for bore sighting. But since I live on the corner of fairly busy streets in a residential area I was getting too many looks and stopped. Now at home I use a magnetic scope level setup or I wait till I go to the property and use the edge of a target

Use a plumb bob like Jason said, turn the lights out and shine a flashlight through the objective lens. The reticle will project onto you plumb line.

I picked up the "Nevel" from DNZ. Aligning a scope is simple and fast.

^^^^^^^ This, plumb bob will will insure accurate leveling all the way through your elevation turret. Use some sort of level mounted onto your rail or scope after your scope aha been properly mounted to insure your rifle is always level prior to taking a shot.

The Reticle Tru aiming device is foolproof, and makes sure you get the reticle in your scope aligned with rifle bore, which IMO is paramount.

https://parabola-llc.com/

Here's a cool way to validate your reticle alignment demonstrated by Bryan Litz. I do this on all new long range scopes on my rifles this sitting at my work bench in my garage and setting up a MOA grid 100 yds away in the vacant lot across the street. I clamp my rifle in a barrel vice, level it and follow the steps in the video. Its very accurate and I didn't even need to fire a shot. It also validates the turret accuracy and if it's off you can apply an Correction Factor via your ballistics calculator.

Tall Target Test

I've had guys look through the scope on one of my rifles and tell me the cross hairs are tilted. I never argue with them and just let it pass they don't realize how easy it is to cant or tilt a rifle when shouldering it.

As others have stated, the scope should always be mounted with the scope's horizontal axis positioned correctly with that of the rifle so the shooter can remove the natural cant when taking aim at the target.

I have done it both wys. Leveled with a level and a plumb line, also leveled it just by eyeballing it standing unsupported. The latter, usually looking at a doorframe or window frame etc and usually with an air rifle and done in haste. The reason not to use a plumb line when not using a level? Because if it doesn't matter enough to use a level then why go to the trouble of using a plumb line.

At some point down the road, an eyeballed scope always becomes apparent for me. Both in looking through the scope and in use.

If you are gonna go to the trouble of mounting a scope and getting it dialed in, might as well do it right and level it properly. If it matters on a air rifle shooting ten to thirty yards, I can only imagine what it might do with some of the stuff yall are into.