Off the wall question

KnotRight

KnotRight

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Does it matter when putting a scope mount on a rifle if the base screws are on the left side or the right?
The reason for asking is when I lapped a set of rings, it was very important to keep the front one up front.
 
Tim, the rifle that I am working on now I am putting a 20 MOA rail on it. The rifle is a bolt action 22 LR where I am not sure it will matter what side the screws are on. Please explain the cant on a 20 MOA rail. I understand the front to back slope.
But on an AR style rifle or rifle with a lot of recoil , will it have an effect on the screws with a lot of shots down range?
 
KnotRight said:
Tim, the rifle that I am working on now I am putting a 20 MOA rail on it. The rifle is a bolt action 22 LR where I am not sure it will matter what side the screws are on. Please explain the cant on a 20 MOA rail. I understand the front to back slope.
But on an AR style rifle or rifle with a lot of recoil , will it have an effect on the screws with a lot of shots down range?
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You have 2 components in play....

- Scope Base/Rail
- Scope Rings/Mount


The base/rail bolts to the rifle's receiver and the scope rings/mount connect to the rail. Pretty simple so far, eh?

When you add in a 'cant' such as your 20MOA rail you are purposefully mounting the scope with an incline (relative to the receiver/bore) in order to gain more elevation adjustment from your scope - you're giving the scope a 20MOA head start so to speak.

The 'cant' can be introduced via the base/rail (your case) or the rings/mount. It's important to know which.

If it's a 20MOA rail/base - the part that bolts directly to the rifle's receiver - then you need to orient it such that the incline is higher in the back and lower towards the bore. Whether that means the screws are left or right depends on the rail system. Set the rail on a level surface and get a very long level or very sensitive level to tell which way it goes; 20MOA is less than a degree off level. In this case you mount the base/rail ensuring the cant is correct while the rings/mount have no 'front' or 'back'.

If the base/rail is level and your mount/rings have the cant, then same principle applies - the base/rail is flat and you need to pay attention to the orientation of the rings with regard to fore/aft incline.


0-moa-rail-versus-20-moa-base-2.jpg
 
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If my answer is missing the point...

NO. It doesn't matter at all if the screws are inserted left to right or right to left so long as the rail/mount/rings are oriented properly for the 20MOA cant.
 
Also thanks!

So, if I'm reading @Tim correctly, the specific ring set may - or may not - have the front~rear cant built in? I.e. "front" ring is shorter than the "back" ring, gives proper directional tilt to scope. If one puts that "front" ring on the back, then that puts the front~rear cant backwards (or, in the case of a sloped rail, cancels out the rail slope). ?
 
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Windini said:
Also thanks!

So, if I'm reading @Tim correctly, the specific ring set may - or may not - have the front~rear cant built in? I.e. "front" ring is shorter than the "back" ring, gives proper directional tilt to scope. If one puts that "front" ring on the back, then that puts the front~rear cant backwards (or, in the case of a sloped rail, cancels out the rail slope). ?
Click to expand...


Correct.
 
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I'm right handed so the screw heads are on the right side.
 
You're not likely to 'see' the cant with the naked eye, so pay attention to packaging and directions.

20MOA is only 1/3 of 1*
 
KnotRight said:
Simple question.....does it matter if the screws that hold the mount to the rifle be on the left or right hand side of the rifle?
Click to expand...


Yes, might be simple....but, words matter and we appear to use them differently, or i may just be dim.

Given your Original Post: "Does it matter when putting a scope mount on a rifle if the base screws are on the left side or the right?" and likewise your reply, "Screws that hold the mount to the rifle....."

I understood you to query concerning those screws which secure the base/mount to the weapon. Hence, my confusion. (Given minor exception/in my experience, base/mount screws are most often installed inline, rather than left to right. An example of exception would be the rear scope base/mount for a Win 94 AE which is drilled and tapped for L and R screws.)

Now I see, you are asking about the screws that secure the scope ring to the base/mount that attaches to the rifle.

So.....L or R, your preference.
 
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I concur with what is stated above. I have two Spuhr IDSM that are oriented to face with the level back toward the operator. I recently purchased Spuhr's Hunter mount and oriented it with the wedge level consistent to that of the IDSM mounts, so that's why it is oriented as such on my Sauer 100, but I've seen it oriented opposite as well. There is no cant in the Hunter mount, nor is there a level, so it is really up to the end user which direction they orient the mount.

The only time I would imagine it would be an issue is if the bolts were to be in close proximity to moving items where your fingers come into close contact (i.e. FN SCAR charging handle). They tend to eat up your knuckles on that rifle with low mounts.
 
Goofyfoot2001 said:
OK so I just learned here today that I can now use my crappy scope for longer range shooting. That is awesome. How is it I never heard of this 20 moa rail and never thought of it?
Click to expand...


Depends on how 'crappy' your scope is. You'll need to have 20+MOA (~6 MIL) of adjustment DOWN to make up for the cant. So, your scope would be advertised as having 40MOA/12MIL or more of total elevation adjustment.
 
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