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Proper ring height determination

48K views 57 replies 37 participants last post by  Eccentric 
#1 · (Edited)
There has been a great number of posts regarding which rings to buy for Brand "X" scope. While every single scope on the market has a different sized objective bell, it is seems to be massively confusing which rings to purchase. Not every manufacture uses the same measurement values for low, medium, high, and extra high classifications. This post is to help alleviate some of the major confusion.

Here are a set of pictures to denote two different medium ring sets. They are the Warne Permanant attach and the Burris Zee.
3/4 view


Front:


Bottom:


Mounted on a Picatinny rail for my Mark 22/45:


It is not very difficult to figure out the height for the set of rings you wish to purchase, in combination with the bases you are using once you do two crucial measurements. The Savage 93 and Mark II have the same diameter receiver and base height from the factory. The height of the stock bases are 0.141". It is measured at the thinnest portion between the receiver radius and the top of the base. For a Ruger 10/22 using the factory rail, it is 0.310" from the top of the base to the top of the bull barrel.

If you do not have a good digital caliper, may I suggest this one for a modest investment. Please choose whichever one you feel like purchase, just get one. You can usually find the dimensions of the objective from the manufacturer or from sites like MidwayUSA. You want to measure the largest part and most rearward part of the bell. It is the piece you are trying to have enough clearance to operate.

Simmons 4-12x40AO


Tasco 6-24x44AO:


Setting a goal of .125" separation between the lowest point on the scope and the top of the receiver/barrel is preferred. You want the scope to be as close as possible without touching while allowing the adjustable objective (if your model has one) and lens covers to function properly.



Here is the formula: (Base height + ring height) - (Objective bell diameter/2 - Tube diameter/2) = Scope clearance.

The goal is to solve for the ring height. I will use the Bushell Elite 3200 4-16x40AO as an example. The specifications are:
Objective bell diameter: 53mm (2.087")
Tube Diameter: 1.000"
Stock base height: 0.141"

To work out the bare mininum ring height you have run (Objective bell diameter/2 - Tube diameter/2)- Base height. It looks like this
(2.087/2 - 1.000/2) - 0.141 = 0.403"​
Add 0.125" to give the proper clearance and you need a ring height of 0.528". To get the correct measurement, the height is taken from the smallest distance between the scope tube and the base of the ring (where the ring sits on top of the bases). You could vary this figure plus or minus .050" depending on preference. Using my favorite brand of rings, the high Warne Maxima Permanent-Attachable rings are 0.525" high, giving me an affective scope clearance of 0.122" I am partial to this ring set since there are no exposed bolts to snag, use two bolts to put tension on the base, and they have a very clean appearance.

To help you make a very quick decision as to which height to look for, I have included the following values: stock bases, 1.000" scope tube and 0.125 clearance"
Objective size:........... 1.800 1.900 2.000 2.100 2.200 2.300 2.400 2.500 2.600
Suggested ring height:.... 0.384 0.434 0.484 0.534 0.584 0.634 0.684 0.734 0.784​

If you are working with a 30mm tube, you have to factor in a tube diameter of 1.181" diameter. Here are the suggested heights:

Objective size:........... 1.800 1.900 2.000 2.100 2.200 2.300 2.400 2.500 2.600
Suggested ring height:.... 0.384 0.343 0.393 0.443 0.493 0.543 0.593 0.643 0.693​

I hope this allows you to make a more informed ring purchase for your Savage. Sticky this.
 
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#3 ·
You have it figured out pretty well. I ended up making a spreadsheet so I could consider the variables of different rings and different base height options besides the factory 0.141" or so ones. It was a good thing because I changed my scope choice at the last minute and it was easy to scramble and make the necessary changes in rings and bases - and I had to change both.

The only complicating factor that I see missing beside the alternate base height options, is that some scopes are long enough that the objective fits out over the step down in the heavy barrel. You gain about 0.060" clearance if the objective fits there.

Ron
 
#5 ·
Ron, you are right. That step down can come into play if the bell can be set forward 4.5" of the front base. Most of the really high magnification scope might be able to do that.
 
#9 · (Edited)
You will not need to epoxy the Warne rings. They are stout. Trying to recall from memory, since I am in Minnesota waiting on a flight back to California, the rings are wider than the Burris. The mounting involves a key going into the slots of the base and rings. This prevents them from moving with recoil. Here are a couple of more comparison pictures







I like them for how they mount. To put them on, you put the halves over the scope tube and just get the screws started. They will be loose enough to fit the bottom over the base and recoil key. Once you have placed them on the bases, start tightening the lower screws only. Before the rear screws are completely tightened to 65in/lbs, I pulled the rings forward, engaging the recoil key against the rings and bases, then finish tightening them. Here they are mounted to my wife's 10/22.



With the rings securely mounted to the bases to where they cannot move, the scope can still slide back and forth so you can set your eye relief. In my case, I used my shooting kits to set the rifle in my shooting position, then moved the scope back and forth until I had a perfect sight image. The scope was marked for that distance. It was moved to my cleaning stand so I could level the rifle, then the scope. After everything was in alignment, I tightened up the top screws to 20in/lbs.

One difference I have seen between the Burris Zee rings I initially bought and the Warne were the lack of machining marks in the scope contact area in Warne. On my .308, I have a set of $240 rings and bases from Talley. I am thinking of switching them out for Warne bases and rings.
 
#16 · (Edited)
New pictures added above for better clarification.

Now that I did my own math correctly, here is the spacing I have between my scope and barrel.



Assembled gun
 
#18 ·
Almost all those pictures were taken outside using indirect ambient light. For the tight shots, the macro function on the Canon PowerShot A540 was used. Those are sized down from its native 6MP size to either 1024x768 or 800x600.
 
#21 ·
thanks for the informative post!

I have a 50mm scope on my BTVS and using Weaver extra high Quad Locks. My clearance is just about the same as yours. I cant use the lens cover but I think I'm just going to put a clearance notch on it. I have a srt of Burris Signature Zee High rings on back order but will cancel the order as they are shorter than the Weavers, and look at a set of the Warnes.
 
#22 ·
Signature Zees Please

Your example shows the regular Burris Zee rings. The Burris Signature Zee rings with self-aligning inserts is the way to go.

No lapping required for perfect fit, always aligned, no damage to scope, easily shimmed with cheap offsets from Burris. Check the Signature Zee rings out at the Burris site. I wouldn't use anythng else for any amount of money.
 
#23 ·
Great Post!! It realy helped me figuer out what hight rings I neaded to mount a Mueller APV on my Mark II BTV. I came up with a hight of .519 and ordered a set of Warne Max. Prem. Att. high (.525),thay should be here on tue. Thanks for the great post I will let you know how it works out. Purp
 
#24 · (Edited)
This has me confused :eek:

My objective measures 2.20" that puts me at needing a .594 height ring set from Warne. However they make a .525" too short and a .650" most likely too tall. I like their ring set up it seems very secure. But were only talking a 22lr here.

Is there another manufacture that has a set up like Warne that will work on my MKII BTVS with a BSA 6x24x44 that measures 2.20". I do not have the rifle yet but have the scope. I would hate to receive the rifle then have to wait longer yet to get the scope rings! I am running out of nice weather to go sight her in!!
 
#25 ·
To work out the bare mininum ring height you have run (Objective bell diameter/2 - Tube diameter/2)- Base height. It looks like this:
(2.200/2 - 1.000/2) - 0.141 = 0.459"
With the Warne Medium ring (0.525"-0.459") will give you a clearance of 0.066". This might be very tight. Make sure you measure the largest part of the objective including the adjustable objective.
 
#27 ·
how does a base with built in elevation factor into the maths? I will be putting 25 moa RT base on mine and would like to avoid the ring swap shuffle. I haven't played with ramped bases before so im not sure if the put the scope at a significant angle that affects ring height.
 
#28 ·
Great post! thanks for your guidance. I am one who seeks the help you just provided because I purchased x-high rings that i thought would fit my Vortex 50mm scope for my Savage 93r17 BTV. To my disappointment they did not so I will follow your formula and go forth!!:bthumb:
 
#38 ·
If you go to midwayusa and look up the scope you are concerned with, it will list the outside diameter of the objective bell. Why scopes are not ALWAYS listed with this information included blows my mind. The same issue I have with base heights and ring heights not being listed. Otherwise, it's just a guessing game in a sport where our machinery and accuracy is measured in gradients of thousandths or more.
 
#32 ·
The Warne rings are top quality. As long as you use a quality base, there should be no reason to have to lap the rings.

I think Ken Farrel is now making a base for the Savage rim fires. I've been told it's not cheap, but he makes the best bases available anywhere. I'll try to find a part number.

He holds the base to no more than .002 difference from the front to the back on the centerfire bases.
His bases are by far the best on the Savage centerfire. I've never seen a bad one. The FG-Forcehard Line Mount for the centerfire is fantastic, the rimfire base should be the same.

Best Regards, John K
 
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