New Scope - What Ring Height?

beeker77 · April 4, 2014, 10:49 PM

Ordered a SIGHTRON SIII 8-32x56mm 30mm to be installed on a 20 MOA base (adds about 1/2-inch to the scope height). Awaiting delivery.

Best Guess: What height scope rings for this setup? "Normal" (low), medium, high, or extra high.

On the intended rifle, the butt stock cheek rest is adjustable for height.

geetarman · April 5, 2014, 01:26 AM

Probably high will work. I have one 56mm bell scope and I do not recall ever using anything taller.

Do some googling of ring makers and they will likely have a chart of suggested ring height.

Make sure you know what diameter tube you have before you order the rings.

SSA · April 5, 2014, 10:39 AM

It depends on what rings you're planning to use. Some brands are different than others. If your base is really that tall, there are a number of medium rings that will fit, and maybe some lows.

Brian Pfleuger · April 5, 2014, 10:46 AM

http://www.brownells.com/.aspx/lid=1...g-Height-Chart

Note that the chart basically assume a straight profile barrel.

Nathan · April 6, 2014, 10:14 AM

What rifle? I have a 50mm obj on a Savage Bull Barrel in low rings. . . .Gun, mount, barrel all matter. After that, I just do the math from scope center to action = obj + gap I want -barrel taper change from action top to ~ where the obj bell will be.

so,

B = Base height
R = Ring height (base to bottom of scope tube)
T = Scope tube dia
O = Obj outer diameter (scope mfgr's will give this to you or it is on their site or you measure the actual scope
D = Action top - barrel top (to be reasonably accurate, just lay the gun on a sheet of paper and trace it. Then extend the action line(pretty straight) out over the barrel profile. Using pictures or the actual scope figure out where the bell will be closets to the barrel. Then measure the action line to barrel profile distance.) BTW, I just looked at my gun and guessed and was fine. You will be as good as your guess.
G = Barrel to scope gap MIN

** Convert all units to inches.

Then,
B + R + T/2 = O/2 + G + D or solved for R:

R = O/2 +G + D - B - T/2
**If you did this right, this is your minimum ring height.

Unlicensed Dremel · April 8, 2014, 09:59 PM

Well that 20 MOA base may add 1/2" in the rear, but it actually points the scope "more downward" in front, of course - how much is added at the front of the base? If 1/2" is added over normal at the front, then I'd get medium rings for 56mm (maybe even low). If 1/2" at the rear, then probably high or xtra high.

April 4, 2014, 10:49 PM	#1
beeker77 Member Join Date: July 9, 2006 Location: San Antonio Posts: 96	New Scope - What Ring Height? Ordered a SIGHTRON SIII 8-32x56mm 30mm to be installed on a 20 MOA base (adds about 1/2-inch to the scope height). Awaiting delivery. Best Guess: What height scope rings for this setup? "Normal" (low), medium, high, or extra high. On the intended rifle, the butt stock cheek rest is adjustable for height. __________________ StraightShooter

April 5, 2014, 01:26 AM	#2
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	Probably high will work. I have one 56mm bell scope and I do not recall ever using anything taller. Do some googling of ring makers and they will likely have a chart of suggested ring height. Make sure you know what diameter tube you have before you order the rings. __________________ Geetarman Carpe Cerveza

April 5, 2014, 10:46 AM	#4
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	http://www.brownells.com/.aspx/lid=1...g-Height-Chart Note that the chart basically assume a straight profile barrel. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

April 5, 2014, 10:39 AM	#3
SSA Senior Member Join Date: August 1, 2010 Posts: 641	It depends on what rings you're planning to use. Some brands are different than others. If your base is really that tall, there are a number of medium rings that will fit, and maybe some lows.

April 6, 2014, 10:14 AM	#5
Nathan Senior Member Join Date: July 1, 2001 Posts: 6,334	What rifle? I have a 50mm obj on a Savage Bull Barrel in low rings. . . .Gun, mount, barrel all matter. After that, I just do the math from scope center to action = obj + gap I want -barrel taper change from action top to ~ where the obj bell will be. so, B = Base height R = Ring height (base to bottom of scope tube) T = Scope tube dia O = Obj outer diameter (scope mfgr's will give this to you or it is on their site or you measure the actual scope D = Action top - barrel top (to be reasonably accurate, just lay the gun on a sheet of paper and trace it. Then extend the action line(pretty straight) out over the barrel profile. Using pictures or the actual scope figure out where the bell will be closets to the barrel. Then measure the action line to barrel profile distance.) BTW, I just looked at my gun and guessed and was fine. You will be as good as your guess. G = Barrel to scope gap MIN Convert all units to inches. Then, B + R + T/2 = O/2 + G + D or solved for R: R = O/2 +G + D - B - T/2 If you did this right, this is your minimum ring height.

April 8, 2014, 09:59 PM	#6
Unlicensed Dremel Junior member Join Date: February 13, 2014 Location: Flathead Valley, MT Posts: 2,187	Well that 20 MOA base may add 1/2" in the rear, but it actually points the scope "more downward" in front, of course - how much is added at the front of the base? If 1/2" is added over normal at the front, then I'd get medium rings for 56mm (maybe even low). If 1/2" at the rear, then probably high or xtra high.