Can you figure ring height without the rifle?

[Hammerdown22]

I have a rem mod 7 that is at the smith getting a new barrel.
I just ordered a Scope (Athlon Optics Ares ETR 3-18x50) and i have the scope base. I was wondering if there was a way I could figure out what ring height i needed and get an order in so when the rifle is ready all i have to do is assemble.

 

[_Windrider_]

Ring height calc



(Obj diameter/2)-((obj diameter-tube diameter)/2)+lens cap thickness + cant



(56/2) + ((56-34)/2)+3



28+11+3= 42 mm or 1.65 inches

you can honestly disregard the cant addition If you want but this gets you in the ballpark. The cant is there for for full pic rail calculations. If your rail is only over the receiver then you can usually disregard it. That changes it to around 1.5 inches which is very typical for a 56mm objective

 

[M8541Reaper]

Scope Ring Height and Clearance Calculator

Boom.

 

[Rob01]

With a 50mm objective a .9-1" height should be fine. I run 1" height rings on my 56mm objectives and those are with heavier M24 contour barrels. What contour barrel you getting?

Pic of 56mm objective in 1" height rings. And below is a 50mm objective in 1" height rings.

 

[Hammerdown22]

With a 50mm objective a .9-1" height should be fine. I run 1" height rings on my 56mm objectives and those are with heavier M24 contour barrels. What contour barrel you getting?

Pic of 56mm objective in 1" height rings. And below is a 50mm objective in 1" height rings.

View attachment 7545318

View attachment 7545319

Its a lilja #4 contour barrel

 

[Rob01]

Yeah with a lighter contour barrel a .9-1” would be more than enough. What base is it?

 

[Hammerdown22]

Yeah with a lighter contour barrel a .9-1” would be more than enough. What base is it?

A Murphys pricision 0moa

 

[Hammerdown22]

A Murphys pricision 0moa

These are the rings I was looking at.
This is the lowest height they have in this style.
Too tall?

 

[JLP83]

These are the rings I was looking at.
This is the lowest height they have in this style.
Too tall?

That Spuhr will work height wise but it’s a 0 moa mount and you said your rail was also 0 moa. You’re going to run out of elevation adjustment at distance.

 

[Rob01]

Well too high would depend on a few things like your stock and your face. If an adjustable comb then it will be no issue. If a lower fixed comb and you don’t plan to run a stock pack then might be a little high. Look again at the pic of my 50mm in the 1” high rings and ad about .2” to that and it will give you an idea.

 

[Hammerdown22]

That Spuhr will work height wise but it’s a 0 moa mount and you said your rail was also 0 moa. You’re going to run out of elevation adjustment at distance.

Its chambered in 17 fireball so im probably going to be almost maxed at 500 yards so a drop of around 40 in at 500 yards with a 20gr at 4000 fps is what remington has posted. Would it not work?

 

[Hammerdown22]

Well too high would depend on a few things like your stock and your face. If an adjustable comb then it will be no issue. If a lower fixed comb and you don’t plan to run a stock pack then might be a little high. Look again at the pic of my 50mm in the 1” high rings and ad about .2” to that and it will give you an idea.

Ya its going in a manners MCS-EH8+ and it isn't adj comb.
Looking like im gonna have to go with some rings instead of a mount.

 

[Rob01]

Ya its going in a manners MCS-EH8+ and it isn't adj comb.
Looking like im gonna have to go with some rings instead of a mount.

You could use the mount if you used a stock pack with some adjustment like the Triad Tactical version.

Triad Modular Stock Pack™

triadtactical.com

 

[jakelly]

Ring height calc



(Obj diameter/2)-((obj diameter-tube diameter)/2)+lens cap thickness + cant



(56/2) + ((56-34)/2)+3



28+11+3= 42 mm or 1.65 inches

you can honestly disregard the cant addition If you want but this gets you in the ballpark. The cant is there for for full pic rail calculations. If your rail is only over the receiver then you can usually disregard it. That changes it to around 1.5 inches which is very typical for a 56mm objective

No.

If you are assuming objective lens diameter = scope objective bell diameter, then:
(34/2) + ((56-34)/2) - rail top plane to barrel nearest point which depends on which scope, which barrel contour, and which rail.

@Hammerdown22 , the best way to determine without the scope:
1) Place a straight edge across the top of the rail, which extends out over the barrel.
2) Find the distance from the top of the barrel, to the bottom of the straight edge, at the point the scope will be closest to the barrel (I'll reference this dimension as X). You can use your other rifles or pictures of the rifles of others as a guide.
3) I like to use a margin for error of 6.5mm, which is a touch over a 1/4".
4) Also, 34mm is tube OD 56mm is lens diameter. The objective bell on my 3-12x44 LRTS is 52mm, an 8mm difference. I account for that.

So the equation I would use would be:
(34/2) + ((64-34)/2) - (X - 6.5) = Minimum Ring Height

So if X equals .5 inches (12.7mm), then:
(34/2) + ((64-34)/2) - (12.7 - 6.5) =
17 + ( 15 - 6.2 ) =
17 + 8.8 = 25.8mm or 1.016"
With a bit of time and attention to detail you can get very close with this method. It has never failed me.

 

[_Windrider_]

No.

If you are assuming objective lens diameter = scope objective bell diameter, then:
(34/2) + ((56-34)/2) - rail top plane to barrel nearest point which depends on which scope, which barrel contour, and which rail.

@Hammerdown22 , the best way to determine without the scope:
1) Place a straight edge across the top of the rail, which extends out over the barrel.
2) Find the distance from the top of the barrel, to the bottom of the straight edge, at the point the scope will be closest to the barrel (I'll reference this dimension as X). You can use your other rifles or pictures of the rifles of others as a guide.
3) I like to use a margin for error of 6.5mm, which is a touch over a 1/4".
4) Also, 34mm is tube OD 56mm is lens diameter. The objective bell on my 3-12x44 LRTS is 52mm, an 8mm difference. I account for that.

So the equation I would use would be:
(34/2) + ((64-34)/2) - (X - 6.5) = Minimum Ring Height

So if X equals .5 inches (12.7mm), then:
(34/2) + ((64-34)/2) - (12.7 - 6.5) =
17 + ( 15 - 6.2 ) =
17 + 8.8 = 25.8mm or 1.016"
With a bit of time and attention to detail you can get very close with this method. It has never failed me.

6 in one half dozen in the other. I’ve never had an issue but I’m also not of the lowest rings possible crowd. I like to shoot and be comfortable so all my cheek pieces are adjustable and I get the rings that allow me to be straight behind the rifle.

 

[jakelly]

These are the rings I was looking at.
This is the lowest height they have in this style.
Too tall?

I've looked at the details of your set-up, you are going to want the lowest 34mm rings possible.
Yes, this mount will be too high. In fact, all mounts will be too high.
That's a long scope on a thinner barrel with a 0 MOA rail. Murphy's are a bit lower so that helps. But yeah, you want the lowest rings possible.

 

[jakelly]

6 in one half dozen in the other. I’ve never had an issue but I’m also not of the lowest rings possible crowd. I like to shoot and be comfortable so all my cheek pieces are adjustable and I get the rings that allow me to be straight behind the rifle.

Yeah, that works, too.

 

[MarkyMark007]

everyday same thread?
if you can calculate, than:
example:
objective 50 = 56mm, tube 30mm -> scope BH = (56-30)/2 = 13mm
height of picatinny rail to action = 6mm
barrel BH to action where scope objective goes -> (34-28)/2 = 3mm
13 - 6 - 3 = 4mm.
in this case you need rings BH height 4mm to scope touch the barrel. take few mm heigher.

 

[Rob01]

You don't always want lowest possible as being close to barrel is not important. Being comfortable behind it.

Also being a math professor is not needed to figure this out with a little help from experienced people and then learning and gaining experience yourself. A set of .92" 34mm rings would work but so would a set of 1" height.

 

[Hammerdown22]

Thanks for the help im gonna do a little looking at some different mounts and try to stay 1" or less