Mounting a scope

tlino · Jun 9, 2018

I am mounting a scope on a sporterized Mauser. I want to use it for long range target shooting, which I am new to. I am taking a course soon and want to have the scope ready. I have a Vortex Viper HS LR 6-24x50.
8mm Mauser with a 24" bull barrel.

I want to zero the scope at 100 yards adjusted full down to give me 68 MOA of up adjustment.

I need to adjust the base to make this work.

My question is:
I have a 66 yard target in my backyard, but can't shoot in this area.
If I bore sight the rifle and raise or lower one end of the scope base to get the crosshairs on the target, should that get me on paper when I get to the range? (50 and 100 yards targets)
Is it that simple?

[/url][/IMG]

dist1646 · Jun 9, 2018

You have a 24 foot bull barrel? That thing must require a trailer. LOL! Think you meant 24 inch.
Good luck with your project.

tlino · Jun 9, 2018

dist1646 said:
You have a 24 foot bull barrel? That thing must require a trailer. LOL! Think you meant 24 inch.
Good luck with your project.

Thanks for pointing that out. Fixed it.

Ranchero50 · Jun 9, 2018

As a theoretical exercise I'd zero it at 100 yards and see where the scope is set, then do the math to calculate what the mount needs to do to get the adjustment where you want it.

tlino · Jun 9, 2018

Ranchero50 said:
As a theoretical exercise I'd zero it at 100 yards and see where the scope is set, then do the math to calculate what the mount needs to do to get the adjustment where you want it.

I can't zero it. Not enough internal elevation in the scope. This rifle was not built for a scope, so I have to use what is available and make adjustments.

Ranchero50 · Jun 9, 2018

tlino said:
I can't zero it. Not enough internal elevation in the scope. This rifle was not built for a scope, so I have to use what is available and make adjustments.

So you have two separate problems?

It needs to zero somewhere and then you can figure out how much angle difference you need at the mounts to run a full scale of elevation.

If the bull barrel is a constant diameter a machinist could put it in a mill and once parallel to the table check the sight mounts to insure they are parallel with the barrel. Sounds like currently your mount is not parallel to the barrel if you can't zero it.

tlino · Jun 10, 2018

Ranchero50 said:
So you have two separate problems?

It needs to zero somewhere and then you can figure out how much angle difference you need at the mounts to run a full scale of elevation.

If the bull barrel is a constant diameter a machinist could put it in a mill and once parallel to the table check the sight mounts to insure they are parallel with the barrel. Sounds like currently your mount is not parallel to the barrel if you can't zero it.

It has nothing to do with the barrel. It is the size and shape of the receiver.

Ranchero50 · Jun 10, 2018

tlino said:
It has nothing to do with the barrel. It is the size and shape of the receiver.

If it has the same diameter over a distance you can use the bull barrel profile to true the receiver and scope mount. A competent machinist or gunsmith will be able to figure it out. Whoever installed your scope mount is an idiot...

tlino · Jun 10, 2018

Ranchero50 said:
If it has the same diameter over a distance you can use the bull barrel profile to true the receiver and scope mount. A competent machinist or gunsmith will be able to figure it out. Whoever installed your scope mount is an idiot...

The receiver does not have the same diameter. It has a much larger diameter in front of the bolt than behind.

I am the idiot. Thanks for the encouragement.

dist1646 · Jun 10, 2018

There are plenty of base set ups for Mauser actions. Look for bases for a '98 Mauser, presuming of course that it is a '98 action. Rings are all pretty much standard. Once you have it on paper, you can calculate whether or not you will need to shim one end of the base/s. Try to find a one piece base so that the centerline of the rings will stay on the same relative plane once it has been shimmed. You want to avoid misaligning the ring centerlines relative to each other so that you do not induce stress issues to the scope.
If it becomes necessary, there are rings that are made with spherical inserts that will help out with reducing scope stress issues due to misalignment of the rings.

tlino · Jun 10, 2018

I really would like someone to just answer the original question.

"If I bore sight the rifle and raise or lower one end of the scope base to get the crosshairs on the target, should that get me on paper when I get to the range? (50 and 100 yards targets)
Is it that simple?"

dist1646 · Jun 10, 2018

tlino said:
I really would like someone to just answer the original question.

"If I bore sight the rifle and raise or lower one end of the scope base to get the crosshairs on the target, should that get me on paper when I get to the range? (50 and 100 yards targets)
Is it that simple?"

OK, if you properly bore sight the rifle, you will be on paper at those distances.

If the base needs to be shimmed, it should be obvious to you when you bore sight. The amount of shims you may need to get to where you desire to be can only be accurately determined once you have shot a group on target.

Doco Overboard · Jun 10, 2018

To prevent running out of scope adjustment bases on 500 -1000 yard rifles bases are usually milled on an elevation correcting angle. The divergence of the angle that can be produced on bases are usually 1/8th or 1/4 of a degree. A minute of angle is 1/60th of one degree or 1.047 @ 100yds. the divergence angle on sloping bases 1/8 of a degree would lower the line of sight about 7.9 in @100 yds 39.5 @500 and 78.3 @ 1000 yds.
You can lose the one piece redfield mount you have and mill off the charger bridge from your action if it hasn't already been done and pick up some Luepold oversize gunsmith bases that can be made to match the contour of the front ring and rear charger bridge surfaces of your rifle, have them drilled and counter bored to match your hole pattern (which should be exactly parallel with your bore so mechanical center line of the scope agrees) calculate the degree of divergence you want and then trial fit everything together to make sure your rings agree with eye relief and parallax for the distance your are shooting. Lap it all together for full contact at the bases and rings and then let her eat.
You might need, some Kimber Brownell classic style scope rings with locks, dovetail mounting bases or Luepold gun-maker bases rings.
Just make sure plus or minus manufacturing differences due to variations in the scope bases, rings, receiver bridge height do not combine to stress, tweak or bend your scope tube. Theses same conditions are also what causes stress on a receiver to a greater or lessor extent depending on severity and could also cause windage or elevation problems especially if coupled with bedding problems.

tlino · Jun 11, 2018

Doco Overboard said:
To prevent running out of scope adjustment bases on 500 -1000 yard rifles bases are usually milled on an elevation correcting angle. The divergence of the angle that can be produced on bases are usually 1/8th or 1/4 of a degree. A minute of angle is 1/60th of one degree or 1.047 @ 100yds. the divergence angle on sloping bases 1/8 of a degree would lower the line of sight about 7.9 in @100 yds 39.5 @500 and 78.3 @ 1000 yds.
You can lose the one piece redfield mount you have and mill off the charger bridge from your action if it hasn't already been done and pick up some Luepold oversize gunsmith bases that can be made to match the contour of the front ring and rear charger bridge surfaces of your rifle, have them drilled and counter bored to match your hole pattern (which should be exactly parallel with your bore so mechanical center line of the scope agrees) calculate the degree of divergence you want and then trial fit everything together to make sure your rings agree with eye relief and parallax for the distance your are shooting. Lap it all together for full contact at the bases and rings and then let her eat.
You might need, some Kimber Brownell classic style scope rings with locks, dovetail mounting bases or Luepold gun-maker bases rings.
Just make sure plus or minus manufacturing differences due to variations in the scope bases, rings, receiver bridge height do not combine to stress, tweak or bend your scope tube. Theses same conditions are also what causes stress on a receiver to a greater or lessor extent depending on severity and could also cause windage or elevation problems especially if coupled with bedding problems.

Thank you. Great answer. Where can I get the Luepold oversize gunsmith base? Exactly what I need. (of course I will Goggle it)

Doco Overboard · Jun 11, 2018

Brownell's

Mounting a scope

The #1 community for Gun Owners of the Northeast

Member Benefits:

tlino

I learn better hands on w

dist1646

Ultimate Member

tlino

I learn better hands on w

Ranchero50

Ultimate Member

tlino

I learn better hands on w

Ranchero50

Ultimate Member

tlino

I learn better hands on w

Ranchero50

Ultimate Member

tlino

I learn better hands on w

dist1646

Ultimate Member

tlino

I learn better hands on w

dist1646

Ultimate Member

Doco Overboard

Ultimate Member

tlino

I learn better hands on w

Doco Overboard

Ultimate Member

Users who are viewing this thread

Latest posts

Forum statistics

Latest threads

Forum statistics

Share this page