20 MOA Rail. Max Range for scope, check my math

nards444

New member
Joined
Jan 14, 2022
Messages
25
I have a 300 WSM (browning x bolt) Just bought a SIG 6x24-50 scope. Ordered a 20MOA rail for it, I know it wont hurt, but thinking do I really need it. Also going to get the SIG custom turret. Scope will be zeroed at 100 yds, 1/4MOA at 100 yds on the scope

Anyways here is my math, scope claims 100 clicks at 25 MOA, funny thing is scope turned all the way down I am counting like 120 some odd clicks, so is the 100 clicks assuming a 100yd zero?

The round I use at 1000 yds would drop 265in, or 26.5 MOA or 106 clicks. which would put scope at stock set up max Range at about the 960-980 range.

I guess Where I don't have a grasp is what will the 20 MOA rail do for me, how much will I extend my range?

Most of our hunting out west is in the 3-500 range. But a few of us guys have taken deer in the 6-700 range. All in all I would want to be set up for 7-800 yds and guess end of the day of the scope got me to 1000 I would be happy.
 

cahunter805

Well-known member
Joined
May 27, 2014
Messages
2,175
There are many factors that affect how much travel/adjustment you will actually have once your scope is zeroed.
Typically you want your scope to have at least 1/2 the available travel once zeroed. Most people try to be zeroed at the scopes midway point in adjustment.
The 100 clicks on your scope is from bottomed out to full max. You won’t have 100 clicks once zeroed.
The 20MOA rail will add elevation without using clicks of your scope giving you much more useable adjustment for elevation in the scope.
 

winmag

Well-known member
Joined
Jan 3, 2018
Messages
761
Location
Colorado
Kind of difficult to understand what question is being asked.

I’m pretty sure that scope has 25MOA of travel per revolution of the elevation dial and 60MOA of total elevation travel.

Based on needing 26.5MOA of correction to get to 1000 yards with a 100 yards zero, I bet it takes about 25MOA to get to 1000 yards based on a 200 yard zero. So if you zeroed at 200 yards instead of 100 yards, it should be able to dial to 1000 yards without turning more than one revolution of the dial.

The 20MOA rail is probably not needed to get to 1000 yards if the scope has 60MOA of total elevation travel and it’s zeroed somewhere around the center of its adjustment range, which would leave about 30MOA of elevation correction left to dial.

But I think the question was more about how the 20MOA rail would influence getting a custom dial cut that is limited to 25MOA of correction. The rail has no impact on that at all. Adding the rail won’t make it dial more than 25MOA per revolution.
 

BenInMT

Well-known member
Joined
Feb 14, 2021
Messages
308
Location
Western Montana
That scope has 60MOA total travel and you will be able to dial for somewhere around half that much so you can go up 30MOA which sounds like even with a flat rail should get you to 1000 YDS. Adding the canted rail lets you put the reticle centered “higher” so you’ll get to take advantage of 20 more MOAs that are already in the scope.
 

nards444

New member
Joined
Jan 14, 2022
Messages
25
Very few shooters should be shooting at live animals in excess of 500 yards, and those few probably understand how MOA rails work, YMMV.

Had a previous set up from 8 years ago and this all figured out then. Just upgrading. Have taken multiple deer past 500 with good shots really not that hard with the right equipment. Appreciate the input
 

cahunter805

Well-known member
Joined
May 27, 2014
Messages
2,175
Kind of difficult to understand what question is being asked.

I’m pretty sure that scope has 25MOA of travel per revolution of the elevation dial and 60MOA of total elevation travel.

Based on needing 26.5MOA of correction to get to 1000 yards with a 100 yards zero, I bet it takes about 25MOA to get to 1000 yards based on a 200 yard zero. So if you zeroed at 200 yards instead of 100 yards, it should be able to dial to 1000 yards without turning more than one revolution of the dial.

The 20MOA rail is probably not needed to get to 1000 yards if the scope has 60MOA of total elevation travel and it’s zeroed somewhere around the center of its adjustment range, which would leave about 30MOA of elevation correction left to dial.

But I think the question was more about how the 20MOA rail would influence getting a custom dial cut that is limited to 25MOA of correction. The rail has no impact on that at all. Adding the rail won’t make it dial more than 25MOA per revolution.
Solid advice here.

Guess I should’ve looked up the scope specs instead of going by the OPs info.
 
Last edited:

std7mag

Well-known member
Joined
Aug 23, 2016
Messages
2,127
Location
central pa
If your scope has 60 MOA of total travel, and IF you are actually centered in the travel with zero MOA sighted in, a 20 MOA rail will give you 50 MOA of elevation that you can dial.
 

nards444

New member
Joined
Jan 14, 2022
Messages
25
If your scope has 60 MOA of total travel, and IF you are actually centered in the travel with zero MOA sighted in, a 20 MOA rail will give you 50 MOA of elevation that you can dial.
Thanks for the info. Based on mostly likely getting something like 30MOA out of the scope I'm not sure the 20 MOA rail is needed and probably looking at with 30MOA on the scope, getting to a range north 1100 or so. Getting the 20 MOA rail without doing the math, probably puts this thing out to 1500 or so, which I dont need.
 
Last edited:

Farmerj

Well-known member
Joined
Dec 12, 2021
Messages
280
The rest for range will depend on the ballistics of an individual cartridge used to determine maximum range.

It’ll shift the zero point in the turret 20 MOA to one side for elevation…

Don’t over think it.

E64DA3C8-C750-4596-9C1D-56B3EF1C18BF.jpeg
 

ImBillT

Well-known member
Joined
Oct 29, 2018
Messages
2,965
You will only have full elevation available if your windage is centered and only have full windage if elevation is centered. You wouldn’t believe how many people think their scope is broken because they dial, but it doesn’t move, when the problem is that the have dialed elevation or windage so far from center that the full adjustment is no longer available.

If you need to dial 30MOA up, you either need a scope with more than 60 MOA adjustment, or you need to make sure that when you’re zeroed at your closest range(usually 100 or 200 yards) your scope is below its mechanical center. You do that by using a base with some MOA in it.
 
Last edited:

Latest posts

Forum statistics

Threads
100,398
Messages
1,587,172
Members
31,512
Latest member
fadilale
Top