I need less eye relief

[hillbillydruggist]

I have an old Ruger mkii 300wm with a boyd stock and recoil pad. I just mounted an old NIB leupold 6x fixed power. I have the scope slid back in the stock rings as far as it will go. I am only shooting reduced power reloads, so scope bite is not ever going to be a problem.
My problem is that i have to strain far forward to not get any dark spots in my view, am I doing something wrong? Is there a fix?
First time I have had this kind of problem.

 

[Rsadams]

Thinner or removal of recoil pad...? Just a thought....

 

[DirtySteve]

How about a picture..?

 

[savagedasher]

Shortened the stock
My hunting gun has 14 inch pull
And it is too long with winter clothes
It was 15 3/4

 

[Bart B.]

You can have a negative diopter lens the diameter of the eyepiece made to increase eye relief. But it will also lower the scope magnification a little bit. You'll have to back the eyepiece lens out .2 to .3 inch as you've increased its combined focal length. A -4 or -5 might work.

Find an optician who'll let you try some negative diopter lenses to find the right size. Lenscrafters can Lake one for you. Edmund's Scientific may have one the right size.

Mount it with a Butler Creek cover.

 

[Rancher Mike]

Some of the Ruger #1 have a problem with positioning the scope far enough back, you might check on how they resolve this.

 

[Bart B.]

There is another aspect called exit pupil

I don't think that's an issue as it's gonna get bigger with lower scope powers.

 

[hogpatrol]

What bases and yes, a photo would help.

 

[hogpatrol]

Here's a question
Why would a person need less eye relief?
Most people want more

Full field of view, especially on a hunting rifle.

 

[Bart B.]

That depends on the objective lens diameter now doesn't it

Yes, but power is half the equation. Obj diameter divided by power equals exit pupil diameter.

Scope power equals objective combined lenses focal length divided by eye piece combined lenses focal length. Eyepiece normal focal lengths are typically about 2 inches. A 20 power scope's objective lenses have a combined focal length of 40 inches. Adding a negative diopter lens on the eyepiece increases its combined focal length.

Why are 20X scopes shorter than 40 inches? They're a telescope lens system, not a long lens system. That's the technical terminology difference. 500mm SLR camera lenses are telesopic (telephoto) not about 20 inches long, but much shorter, aren't they?

 

[BoydAllen]

If you don't want to shorten your stock, here is a possible option.
https://www.google.com/search?biw=1....894.0j7......1....1..gws-wiz-img.QiZaxHJ4gFo

 

[Bart B.]

I know the math

That's good. By your post, I didn't think you knew both exit pupil and magnification ones.

 

[BoydAllen]

Isn't exit pupil the actual working objective diameter (which may be less than the lens diameter because of baffling) divided by the scope's magnification? I am working from very old memory here.

 

[hillbillydruggist]

Sorry for bad pic

 

[BoydAllen]

I was taught to divide the objective into the power
Addendum- no hair splitting just overview

Think about that for a bit. For the same effective objective diameter, the higher the power, the smaller the exit pupil. Just check out some manufacturers' spec's. Lets do a couple of examples. With the same 40mm objective, the exit pupil for a 6X would be 40/6 = 6.7mm. On the other hand if we do the same calculation at 24x we get 40/24= 1.7mm.

 

[savagedasher]

Check with the scope manufacturer they give the eye relief
Most changes with power
Then your have two choices
Get the scope mount that let you get
It
Or. Adjust the stock
Most inexpensive have short eye relief

 

[Bart B.]

I was taught to divide the objective into the power
Addendum- no hair splitting just overview

then a 10 power scope with a 50mm lens would have a 2/10ths millimeter exit pupil, about .0078 inch.

 

[Papa Charlie]

I would look at an extended ring that moves the scope back as was suggested earlier. It is the simplest and cheapest way to make the adjustment without having to modify your scope or rifle.

 

[Bart B.]

I'm kinda busy today Bart"
Maybe call Sightron and take it up with them.
J

Another way to calculate exit pupil is to divide the eyepiece focal length in millimeters by the telescope's focal ratio (f/stop) like camera lenses have. If the 10X scope eyepiece has a 50mm focal length, its objective lens combined system (all lenses in front of the second focal plane) has a 500mm focal length. If its main objective lens diameter is 50mm, the f/stop equals 500 mm focal length divided by 50 mm lens diameter or f/10. 50/10 = 5mm exit pupil. Same as a 50mm lens divided by 10 power

 

[hillbillydruggist]

I would look at an extended ring that moves the scope back as was suggested earlier. It is the simplest and cheapest way to make the adjustment without having to modify your scope or rifle.

i'm waiting on a reply from Ruger & Leupold, but i think that is what i am going to do