Action Leveling

[Richard22]

No doubt the topic of scope leveling has come up many times, often including mention of the gadgets that are available to make it easier. But IMHO, the greater challenge is finding the best way and tool to level the action when mounting a new optic. After all, if the action isn't level, what difference does it make if anything above it is level. It's a topic that brings to mind where is the best place to focus when leveling an action? I have always used the bolt rails as the reference point and use a simple grinder wrench like the one shown to level an action. The handle is just right size to slide into the rear of the action and across the bolt rails so that a level can then be placed on it.

 

[Fire_9]

If a level action is really that important to you, check out the EXD engineering scope leveling tool. One of the easiest ones to use.

 

[antelopedundee]

Does it indicate what MOA size of rail you might want to use?

 

[Richard22]

If a level action is really that important to you, check out the EXD engineering scope leveling tool. One of the easiest ones to use.

It appears this tool only ensure the axis of the barrel and scope are in vertical alignment. As I understand the basic geometry, the action must be level when this alignment is made so that all three (action, barrel, and scope) are all on the same vertical axis. With the action canted any number of degrees from level, the scope and barrel can still be positioned so that they are on the same vertical axis.

I would be interested to know what other surfaces or parts of an action do others use when leveling it before installing and checking everything else?

 

[Caseknife]

I have the EXD tool and it works great. From your drawing, I know it is exaggerated, but that would indicate the ring bases were not mounted correctly to the action, screw holes not true in the action. How do you go about fixing that?

 

[winmag]

This actually doesn't matter.

If the scope is level, the adjustment will be true. The only error will be the horizontal distance between the center of the bore and the center of the scope, and this error does not change with distance. If the scope is 1/4" right of the bore at the muzzle, the projectile will impact 1/4" right at 1000 yards.

Many competitive shooters intentionally hold the gun canted. Check out David Tubb's highpower standing position. His sight is level, his rifle is intentionally canted. And he's won every match there ever was in highpower.

 

[Fire_9]

It appears this tool only ensure the axis of the barrel and scope are in vertical alignment. As I understand the basic geometry, the action must be level when this alignment is made so that all three (action, barrel, and scope) are all on the same vertical axis. With the action canted any number of degrees from level, the scope and barrel can still be positioned so that they are on the same vertical axis.

I would be interested to know what other surfaces or parts of an action do others use when leveling it before installing and checking everything else?

View attachment 366393

You make my head hurt. You are completely wrapped around the axle on this and talking about things that don't matter. The center of the bore and the center of your scope are what you should be worried about and that is even debatable. As winmag stated, the scope and action can be out of vertical alignment of each other as long as the reticle travels in line with the fall of gravity.

 

[WapitiBob]

As winmag stated, the scope and action can be out of vertical alignment of each other as long as the reticle travels in line with the fall of gravity.

yep

 

[Richard22]

yep

I suspect we can all agree the axis and tilt of the barrel is what is most important when taking shots, the barrel always having some upward tilt in order for the bullet to reach a distant target. The issue that comes into play is that when all three components are not in the same vertical axis, the vertical distance between each of them changes with the degree of cant. This can be visualized in the diagrams. Change these distances and you change the travel of the bullet relative to the settings of the scope and barrel.

Yes, I can see these distances staying constant IF the shooter is able to cant the rifle exactly the same with each shot. However, it would seem shooter accuracy would be improved if all three where in vertical alignment as a set and constant benchmark. Otherwise, those gangsta's who like to point a pistol tilted at a 45-90 degree angle would be equally accurate with each and every shot.

Granted, this is something that becomes more important as target distance increases.

 

[Fire_9]

I suspect we can all agree the axis and tilt of the barrel is what is most important when taking shots, the barrel always having some upward tilt in order for the bullet to reach a distant target. The issue that comes into play is that when all three components are not in the same vertical axis, the vertical distance between each of them changes with the degree of cant. This can be visualized in the diagrams. Change these distances and you change the travel of the bullet relative to the settings of the scope and barrel.

Yes, I can see these distances staying constant IF the shooter is able to cant the rifle exactly the same with each shot. However, it would seem shooter accuracy would be improved if all three where in vertical alignment as a set and constant benchmark. Otherwise, those gangsta's who like to point a pistol tilted at a 45-90 degree angle would be equally accurate with each and every shot.

Granted, this is something that becomes more important as target distance increases.

I can't tell if you're serious or if you're trolling but that's what a level is for. You set a tube mounted level with your reticle and that is your constant benchmark.

 

[Richard22]

The folks at Wheeler offer their own solution for ensuring the action, barrel, and scope are all centered on the same vertical axis, assuming the bolt rails, bore, and base screws are all centered from the factory.

My OP was only to draw attention to other ways that I and others may have found to level the action, making this the initial baseline when mounting a new scope.

 

[ImBillT]

I suspect we can all agree the axis and tilt of the barrel is what is most important when taking shots, the barrel always having some upward tilt in order for the bullet to reach a distant target. The issue that comes into play is that when all three components are not in the same vertical axis, the vertical distance between each of them changes with the degree of cant. This can be visualized in the diagrams. Change these distances and you change the travel of the bullet relative to the settings of the scope and barrel.

Yes, I can see these distances staying constant IF the shooter is able to cant the rifle exactly the same with each shot. However, it would seem shooter accuracy would be improved if all three where in vertical alignment as a set and constant benchmark. Otherwise, those gangsta's who like to point a pistol tilted at a 45-90 degree angle would be equally accurate with each and every shot.

Granted, this is something that becomes more important as target distance increases.

If you have a scope level, and it reads level on every shot, then your cant was the same.

 

[ImBillT]

This actually doesn't matter.

If the scope is level, the adjustment will be true. The only error will be the horizontal distance between the center of the bore and the center of the scope, and this error does not change with distance. If the scope is 1/4" right of the bore at the muzzle, the projectile will impact 1/4" right at 1000 yards.

Many competitive shooters intentionally hold the gun canted. Check out David Tubb's highpower standing position. His sight is level, his rifle is intentionally canted. And he's won every match there ever was in highpower.

View attachment 366397

I think this is functionally true more than it is conceptually true.

If your scope is mounted to offset to your barrel, but you hit where you’re aiming, then the barrel and scope were angled toward each other, and bullet trajectory intersected the line of sight at the zeroed range. In real life with rifles, we’re generally talking about fractions of an inch of horizontal offset, and hundreds of yards of bullet travel to the zeroed range so the angle is so incredibly small, that the results are functionally just as you say. It doesn’t matter. Don’t worry about horizontal offset. This is especially true for Tubb. He’s usually shooting pretty long distances. If he zeroed a rifle at 300yds, with his sight offset 1/4” right, then his groups would center .58” left of his aiming point at 1000 yards. Well heck. No one shooting good enough to notice that. On the other hand, if you mounted a scope 10” left of your barrel and sighted in at 10 yards, then took a shot at 100 yards, you would be 90” right of your aiming point. But we don’t mount sights 10” offset horizontally, and not many people sight in at 10yds and 100yds. I could see this maybe turning up with a handguard mounted laser sight or something like that.

But you’re right to say that hunters here needn’t be concerned.

And maybe I’m wrong. I could be misunderstanding something.

 

[millerkiller77]

The folks at Wheeler offer their own solution for ensuring the action, barrel, and scope are all centered on the same vertical axis, assuming the bolt rails, bore, and base screws are all centered from the factory.

My OP was only to draw attention to other ways that I and others may have found to level the action, making this the initial baseline when mounting a new scope.


View attachment 366419

I love the lapping bars that wheeler provides in the kit, but the plastic levels are comical. The magnetic offset action level is especially fun.