Ring Height Info - How to Measure Correctly

Oct 9, 2011
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Virginia
Re: Ring Height Info - How to Measure Correctly

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BravoSector1</div><div class="ubbcode-body">For Savage 10FCP in a HS stock.

Optics: Vortex Viper PST FFP 6-24x50
Base: Badger Ord 20MOA
Rings: Badger Max 50 standard/low (M40)

Perfect fit with just enough for the BC cap. </div></div>


I ended up getting the same scope and rifle. I went with the TPS 20 MOA steel mount and the TPS steel LOW(.925") rings from SWFA. Going to contact them tomorrow, ring height is perfect but one of the rings doesn't want to tighten up and feels loose on the base.
 
Sep 26, 2011
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Re: Ring Height Info - How to Measure Correctly

Just wanted to add my method for figuring scope ring height because I didn't see it here. First let me say I typically deal with flat top stuff, so this equation: [rail height + ring height] - [bell diameter x 0.5] doesn't fully apply, and leaves something to be desired.

Also, my way is a little easier, as we typically choose a rifle, then a scope, a scope base, and then the rings to bring it all together. First you take the largest diameter (typically objective lens diameter), minus your tube diameter, and the take that number divided by 2. The reason you divide by two is simple. There is only half of that objective diameter that will be below the scope's center line. For example, on a scope with a 50mm objective with 30mm tube, it would look like:

50mm-30mm=20mm/2=10mm.

This means that you would need at minimum a 10mm ring height to clear your flat top rail. On conventional scope designs (those with an ocular bell that is slightly larger than the tube diameter, but still smaller than the objective bell), you do not have to worry about the ocular bell's clearance unless you have BUIS or fixed sights in the way. Just remember the numbers advertised are the lens measurements, and the actual outside diameter of the objective bell will be several millimeters more. To make it easy we will just use some common, even numbers, but you should have the scope in your hands, or at the very least call the manufacturer to find out true outside dimensions before ordering rings.

In the even that you are using a bolt action rifle, or some other setup where you need to take ring height and base height into account to bring the bottom of your objective bell as close to the top of the barrel as possible, this equation is helpful:

[Bell Diameter-Tube Diameter/ 2]- base height = ring height needed

We will pretend our base height is 5mm installed. So using our example again:

50mm-30mm=20mm/2=10mm - 5mm (base height) = 5mm (our minimum ring height needed is 5mm to make base and bell clear/touch), so in the real world, you would use a 1/4" or low ring and be good to go.

When figuring for fixed sights or BUIS, it's almost as easy as before, but you do not subtract base height.

Example: Figure BUIS is on the same rail as the rings, like on a flat top AR:
50mm bell
30mm tube
5mm base height
10mm BUIS height (folded)
50mm-30mm=20mm/2=10mm of bell radius below center line. Then you go:
10mm bell radius+ 10mm folded BUIS height=20mm ring needed to clear BUIS.

NOW, the only caveat to that is typically your Objective bell is not going to be sitting over your BUIS. Your ocular bell is. SO, if you are going to be fitting buis, it is important to know this dimension and figure it in when trying to clear BUIS. The easy part to that is once you know your ocular bell diameter it is the same math as figuring the difference between your tube and objective diameter, only the difference should be a lot less.

For example, let's say you want to clear the same 10mm tall BUIS with the same scope. Lets say the scope's ocular bell is 38mm. Well, that's 38mm-30mm=8mm/2=4mm, meaning your ocular bell lower radius is 4mm. If you know your buis is 10mm tall, you can simply add the two 10mm+4mm=14mm, which means with 14mm rings your BUIS and ocular bell would be touching, so you would go to a 15-16mm or 5/8" set of rings and clear just fine.
I hope this helps.

Also, I wanted to compile this for you guys really quick. Know first that one inch is equal to 25.4mm. Knowing that, you can almost do a plug and play with the above formulas as such. This is simple subtraction, but:
For 1" scope tubes:
Objective Diameters|Difference between tube and objective. I also did the division by 2 for the heck of it.
32mm|6.6mm/2=3.3mm
40mm|14.6mm/2=7.3mm
42mm|16.6mm/2=8.3mm
44mm|18.6mm/2=9.3mm
50mm|24.6mm/2=12.3mm
56mm|30.6mm/2=15.3mm

For 30mm scope tubes
32mm|2mm/2=1mm
40mm|10mm/2=5mm
42mm|12mm/2=6mm
44mm|14mm/2=7mm
50mm|20mm/2=10mm
56mm|26mm/2=13mm

I also wanted to say that there is nothing wrong with using rings that are measured in inches or mm to get the desired height, as long as you choose the proper ring/ tube diameter. As you can see above, I try to figure everything in MM as far as measurements go for easy numbers, and then pick the closest thing in ring height. A 1/4" ring is 6.35mm. A 10mm ring is close to 3/8" (.39370" to be exact), 1/2" and 13mm may as well be interchangeable, as are 5/8" to 16mm, and 19mm to 3/4". They are so close it is a wash. The nice thing in metric ring heights though, if you need say, 12mm for the barrel and objective to touch, and don't want to jump clear to 5/8"\16mm or 3/4"\19mm, you can usually find rings that are just a few mm taller than touching and be good to go. Just make sure you allow enough clearance for rifle flex during recoil.
 
Nov 29, 2011
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Re: Ring Height Info - How to Measure Correctly

I was looking on midway usa at the weaver 6 hole rings. I am a bit confused on all the numbers. I believe it stated the height was measured from the base of the ring to the bottom of the opening for the scope. I will be getting a weaver scope with a 50mm objective bell and put it on a remington 700 sps tactical. I want to use a 20 to 30 MOA base and butler creek caps. I think I have figured out that I need a set of medium rings from weaver but I dont want to make it too high if it isnt needed.
 
Oct 21, 2003
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South Beloit,Il
Re: Ring Height Info - How to Measure Correctly

I made a device that sits on reciever and with gun shouldered either standing or prone.....with eyes closed in a comfortable/natural position takes a measurement to eye pupil.
It is patented now and I make them @ $125 ea.
bill larson
 
Jan 25, 2011
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Silver City, New Mexico
Re: Ring Height Info - How to Measure Correctly

Am I correct in that I can run 0.82" low Seekins rings on a Rem700 action, 20moa Seekins base, Rock Creek M40 contour barrel? Scope is an IOR 4-16x50mm w/ 30mm tube.

Your help is appreciated.
 
Sep 25, 2007
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Dallas/Fort Worth
Re: Ring Height Info - How to Measure Correctly

My problem isn't how to figure the ring height but how to figure the correct ramp moa for each scope. I have two rifles, each with 20 moa ramps. Using the same rings and scope, I give up 7mils off mechanical zero on one and 20 on the other. I was just telling an engineer friend of mine that what we need is a way to determine how many moa ramp we will need to keep the scope from giving up to much elevation to zero at 100 yards. Any ideas from you engineer/snipers?
 
Aug 4, 2009
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League City, Texas
Re: Ring Height Info - How to Measure Correctly

Shim the rail Brownells sells pre-cut shim packs, get 3 sets and you might have enough for both rifles, might also be able to get a rail with a bit more angle for the one that is 20 off.
 

USAF

Private
Nov 27, 2011
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Alexandria, Virginia
Re: Ring Height Info - How to Measure Correctly

Another aspect of this question relates to the external ballistics of the bullet in relationship to the height of the scope above center bore line. As a general rule, one would normally want to minmize this height. For an AR type rifle, the normal centerline scope height above the centerline bore line is 2.7215 inches. This dimension will help those interested in determining their ballistic trajectory when using a ballistics calcultor.

Good luck all!

USAF
 
Jan 12, 2010
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France
Re: Ring Height Info - How to Measure Correctly

For Rem 700 McMillan A5 stock.

Optics: Schmidt & Bender 5-25x56 PM II
Base: Badger Ord 20MOA
Rings: Do you think Badger Ordnance 34mm High 1.257" would be the right choice?
 

cz777

Sergeant
Mar 27, 2008
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0
Re: Ring Height Info - How to Measure Correctly

need more in put for full length rail sets for ar style weapons -height between scope bells to rail ...
 

m1ajunkie

Full Member
Feb 22, 2010
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Atlanta, GA
Re: Ring Height Info - How to Measure Correctly

Putting together a new precision rifle but I don't have the rifle with me at the moment, but I'm trying to get my rings squared away.

I am running a remington 700 5r LA, USO 20 moa base, vortex 30mm tube and 50mm objective scope. From the formula, it looks like I should be good with medium rings, but I want to be 100% sure.

Here is my math that shows I should be good to go:

(.4375" + .885")- (2.26" x .5)= .1925"

According to the formula I'll be very close, but I'm not sure how to take into account the 20moa rail.
 
Re: Ring Height Info - How to Measure Correctly

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m1ajunkie</div><div class="ubbcode-body">Putting together a new precision rifle but I don't have the rifle with me at the moment, but I'm trying to get my rings squared away.

I am running a remington 700 5r LA, USO 20 moa base, vortex 30mm tube and 50mm objective scope. From the formula, it looks like I should be good with medium rings, but I want to be 100% sure.

Here is my math that shows I should be good to go:

(.4375" + .885")- (2.26" x .5)= .1925"

According to the formula I'll be very close, but I'm not sure how to take into account the 20moa rail. </div></div>

Depends on whose "medium" you are using. For example Nightforce medium is 1.00", their "lows" are .885

With the setup you were talking about .885 would be the lowest I would go personally.
 

Sonic Crack

Desert Tech Solutions
Oct 24, 2011
2,277
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Wellington, Ohio
m.facebook.com
Re: Ring Height Info - How to Measure Correctly

A lot of times I will get the scope and base that I want, then use gauge pins or anything else for that matter to set under the scope and see where it puts the bell of the scope. I dont like to go by low, med or high because like many others have said these can be way diff depending on whose rings you use
 
Feb 25, 2012
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Re: Ring Height Info - How to Measure Correctly

Couldn't find it online so for anyone else a surgeon 1581r with a 1.350 barrel, there is a gap of .385 between the top of the barrel and the top of the base
 
Feb 15, 2012
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Re: Ring Height Info - How to Measure Correctly

What timing...I was on this morning to search out this very topic and maybe ask these same questions if I couldn't find good info. Thanks for saving me from asking a "worn-out" question!
 
May 24, 2012
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IN
Re: Ring Height Info - How to Measure Correctly

Great post, was going to ask if there was an easy way to determine height then I saw this.
 
Apr 27, 2012
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Re: Ring Height Info - How to Measure Correctly

I just bought the Weaver Tac. 50mm Objective rings. I put my Vortex in it. Fits weell but I'm not grouping as well as I would like to. It's a Tikka 300 wm.
 

cmh2007

Gunny Sergeant
Aug 13, 2009
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Katy TX
Re: Ring Height Info - How to Measure Correctly

HeatSeakins, i have something for your calculator. with a porters precision 20moa rail, a swfa 5-20x50 and your medium rail, the scope just barely clears an m24 taper barrel and the zoom ring just barely clears the back of the rail.
 
Aug 2, 2011
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Texas
Re: Ring Height Info - How to Measure Correctly

Maybe someone can help me or verify that I came up with the correct measurement. First some info for yall.

Scope: Vortex Razor HD
Rings: Badger Ordnance 35mm Medium rings
Base: Badger Ordnance 20 MOA
Rifle: Remington SPS Varmint
Stock: Manners T3

Using the formula that was provided here this is what I came up with.

(Rail Height + Ring Height) - (Bell Diameter x 0.5)
(.2755906" + 1.125") - (2.33" x 0.5) = 0.2355906

Now I dont have the scope base yet I found that number somewhere on the internet (if someone can verify that id appreciate it) and ring height from Badgers website. Bell diameter came from Vortex's website. Also if anyone has a vortex with a similar setup can you please pm or post some pictures I would appreciate it.

Also I'm looking at seekin precision rings and base too.
 

MK75

Sergeant
Sep 6, 2012
103
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Oceanside, CA
Re: Ring Height Info - How to Measure Correctly

Great info guys, thanks. I am getting the wife her first AR and she likes her scopes mounted lower than most shooters so this thread was very helpful.
 
Jun 15, 2012
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Re: Ring Height Info - How to Measure Correctly

hi ive got a nightforce br 8x32x56mm and im putting it on remington 700 vssf ii and ive put on an nightforce 20 moa picatinny base and i havent a clue where to start to figure out what size mounts i need i also dont have a calliper so fine measurements is something i cant get, any help is much appreciated
 
Jul 8, 2012
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Tarrant County, TX
Re: Ring Height Info - How to Measure Correctly

Johnnymolloy, just in case you want a good set of calipers cheap... Harbor Freight has their 6" digitals online for $19.99. I have a set and they have been great. I got them for ten at an in-store sale. I've found them to be handy for a variety of measuring tasks.
 

IPSC

Private
Sep 22, 2012
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Galivants Ferry, SC
Re: Ring Height Info - How to Measure Correctly

I know this is a long thread with many good bits of advice...but it seems all the good stuff is rather spread out over the length of the thread.

To aid new guys here, let's see if we can summarize the big points...all are important. We'll be focusing on bolt guns here as the AR platform has its own issues.

Criteria-->

- objective lens (front) needs to clear barrel. The first poster's formula gets us a real good start here, but consider this: you have some latitude to locate the scope somewhat fore and aft to get proper eye-relief. If you move the scope forward, the big objective lens follows the ever-tapering contour of the barrel and provides more clearance the more the scope is forward. Caution, bull barrels have less "taper" toward the front, and don't benefit as much to gain clearance as you move the glass forward. So it just isn't a simple "height" formula, although we need to do "At least" that to get close. Adding front scope covers requires a scootch more room too...bit I guess we can always trim away some plastic at the 6 0'clock position of the covers if all else is OK.

- OK, so now we have the right height for basic clearance, and the front objective lens clears the barrel, with the fore/aft location you chose. What about the rear lens intereference? Some scopes come with big ocular (rear) lenses, and a "low" mount that otherwise seems OK, may show bolt-handle/hand interference as you operate the bolt. Maybe you need to go higher for this.

- proper cheek weld. OK...so now you have proper front clearance, and proper rear clearance, and now you find that your face-placement on the stock is no good, you have to "lift" your face a bit and use neck muscles to get a proper, "centered" view thru your scope without introducing parallex concerns. Frankly, if all else checks out maybe you rig-up a slightly raised cheek piece ( home-made foam, store-bought strap-on unit, fancy store-bought plastic cheek riser, whatever)...but this is another aspect to fix, besides the mechanical interference we try to avoid.

Going as low as possible to get all these 4 things under control (general height based on physical size of stuff, the first equation..plus front clearance,...plus rear clearance,...plus cheek weld)... its all these 4 things for the proper ring height answer.

An additional concern is when we use 15MOA or 20MOA canted bases. It may "tilt" the front of the scope "down" and have the front lens hit the barrel , and it introduces cheek weld issues that are bigger than before to solve.


A method that uses the original formula, plus the modeling clay method.... plus being able to order a few different rings (with return priviledges if you didn't scratch stuff up)...may be the ticket.
 

huckjare

Full Member
Mar 12, 2009
128
0
0
Idaho
Re: Ring Height Questions

I have been a member here for a while now but have never really been on here much. There is so much info on here to answer just about any question. I love it
 
Jun 6, 2011
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31
Northern Virginia
Re: Ring Height Info - How to Measure Correctly

Oh man.. I made a noob mistake mounting my glass on a Remington 700. I took advice from the manufacturer and they were way off. Sounds like this is the place to look for advice!
 
Nov 29, 2012
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Fl
Re: Ring Height Info - How to Measure Correctly

great post! still trying to get it right the first time with Leupy vxl 56mm, 20 moa base and leupy rings!
 
Aug 14, 2010
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Virginia
Re: Ring Height Info - How to Measure Correctly

Who makes this device, where is it sold, etc?

It appeals to my sense of compulsive obsessiveness AND my 'right tool for the job' fetish.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AzizaVFR</div><div class="ubbcode-body">The most ideal way to see what rings your need for the stock you have, according to your melon, is to see just were your eye aligns above the bore. If there was just such a device you could put on your rail with a graduated scale showing you just were your eye align above the bore WITH the rail you have selected. Hmmm....



With these, I can tell you within two minutes where you head aligns in the off-hand, kneeling, and prone positions. The graduations are 0.100". Also with the measurement, it will tell you if you will clear the objective of your favorite scope or not. Why fit you to the scope when it should be fitted to you? </div></div>
 
Re: Ring Height Info - How to Measure Correctly

I understand the measurements, but I don't have the luxury. I have my 40X short action at Predator Custom getting it built. I'm going to mount my 8x32x50 Burris Black Diamond on this rig. I bought a one piece steel base from Ken Farrell, and the 0.92" 6/4 rings from Seekins. I believe I'm going to be clear, but I don't want glass to be too tall. Anyone have this base/ring setup on their Remy with a 50mm objective lens?
 

MPrimo

Sergeant
Nov 17, 2011
390
1
18
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Orange, CT
Re: Ring Height Info - How to Measure Correctly

Is there a point where I am too close to the barrel with the bell of the scope??? I have about .020" on a 6.5 Creedmoor (with a brake). I can live without the scope covers (for now) but will I cause any damage if I shoot it this way? Thanks in advance ... great thread.