15 MOA scope base for one mile?

[Jon Conley]

I’m trying to get setup for a mile and I’m not sure about my scope base.
The rifle‘s an AR-30 and came with a 15 min scope base. I’ve looked around and called Armalite, it doesn’t look like finding a different base will be easy. I’m trying to find out if the 15 minute base will work.
My scope is a Viper HST and it has 65 MOA in it.
Strelok says I need 227 clicks or 57 MOA. Am I thinking about this correctly? I need 57 MOA and I have 65 in the scope, so that gives me 32.5 mins of vertical plus the 15 mins in the base. That gives me 47.5 MOA and I'm left 10mins short if things ended up prefect..
Well I guess it depends on how many clicks I have left once I‘m sighted in. I’d like to sight in at 100 yd.
I’ve never shot past 1,000 yd so I’m just trying to get this right in my mind.

Thoughts?

AR-30 in 338 Lapua
300 gr Berger OTM @ 2880 fps
Vortex Viper HS-T 6-24

 

[badassgunworks]

You need a 30 moa base not 15

 

[Slides]

As above, more base or get a single piece scope mount with more in it. 15MOA base you have will probably only give you half the elevation range of the scope.

 

[Conaso]

Or buy Burris Signature scope rings, i.e., another 20MOA???

 

[AZgeek]

I went with a 45moa base on my 7mm rem mag for this same application distance, but yes 30moa will get you there. Make sure your rings are high enough to clear the front objective from touching the barrel due to the additional cant angle.

 

[Steel head]

I have an HST and with a 20 moa base I had something like 54 moa available.

 

[addertooth]

I went with a 45moa base on my 7mm rem mag for this same application distance, but yes 30moa will get you there. Make sure your rings are high enough to clear the front objective from touching the barrel due to the additional cant angle.

I am a bit confused. With a 20 MOA mount, wouldn't the scope body start pointing more upwards, and you have to adjust your turrets downwards (towards the minimum), to leave you the maximum elevation adjustment to go UP? This would move the front lens of the scope further away from the barrel, wouldn't it? Relative to the front (objective) lens, the rear (ocular) lens would be tilted closer.

I may be wrong here, and if I am, square me away.

 

[Steel head]

I am a bit confused. With a 20 MOA mount, wouldn't the scope body start pointing more upwards, and you have to adjust your turrets downwards (towards the minimum), to leave you the maximum elevation adjustment to go UP? This would move the front lens of the scope further away from the barrel, wouldn't it? Relative to the front (objective) lens, the rear (ocular) lens would be tilted closer.

I may be wrong here, and if I am, square me away.

Bases with offset pull the front Down and rear up.
Like a proper Instagram pose.

 

[Newbie2020]

I like my Burris xtr rings w interchangeable Teflon elevation inserts. It’s super flexible for different circumstances.

 

[addertooth]

I am a bit confused. With a 20 MOA mount, wouldn't the scope body start pointing more upwards, and you have to adjust your turrets downwards (towards the minimum), to leave you the maximum elevation adjustment to go UP? This would move the front lens of the scope further away from the barrel, wouldn't it? Relative to the front (objective) lens, the rear (ocular) lens would be tilted closer.

I may be wrong here, and if I am, square me away.

Thanks... I just had to look at a graphic from Warne to square me away. I got the whole look versus strike thing backwards.

 

[AZgeek]

For this platform, he could also just keep what he has and use an ERA-tac adjustable mount. Pricey but they provide up to like 70 MOA.

 

[Jon Conley]

As I was saying, I talked with Armalite. There are no 20MOA bases available for my rifle. It has it's own custom base holes and aftermarket just aren't made any longer.

 

[Jon Conley]

I do have this old 20min riser. It's made by UTG Leapers, so I'm sure quality is low and I hate the thought of it being on my rifle. The thing is it seems to be a solid chunk of medal, it's heavy but with a rifle that's already heavy it doesn't matter.
So now if I use this I will have the 20 MOA and the 15 that came on the action. Do you think I'll still be able to sight in at 100yds with 35mins in my base?

​

 

[badassgunworks]

The way you calculate what you need to utilize the entire scope travel is take the overall travel from top to bottom in your scope and divide that in half so if your scope has 60 MOA travel you need us 30 MOA base your scope comes reticle centered otherwise you have the same amount of travel up as you do down the total travel from top to bottom is the total travel that the scope has since a parallel mount will only allow you to utilize half of the overall travel you need a can't base to utilize that which is below parallel

 

[Steel head]

I do have this old 20min riser. It's made by UTG Leapers, so I'm sure quality is low and I hate the thought of it being on my rifle. The thing is it seems to be a solid chunk of medal, it's heavy but with a rifle that's already heavy it doesn't matter.
So now if I use this I will have the 20 MOA and the 15 that came on the action. Do you think I'll still be able to sight in at 100yds with 35mins in my base?

​

View attachment 7561255

35 moa won’t zero at 100 with that scope probably.
Also you’ll find at the upper end of travel shading appears and image starts to suffer.

 

[Steel head]

The way you calculate what you need to utilize the entire scope travel is take the overall travel from top to bottom in your scope and divide that in half so if your scope has 60 MOA travel you need us 30 MOA base your scope comes reticle centered otherwise you have the same amount of travel up as you do down the total travel from top to bottom is the total travel that the scope has since a parallel mount will only allow you to utilize half of the overall travel you need a can't base to utilize that which is below parallel

That’s how I figure out needed elevation.

 

[Jon Conley]

35 moa won’t zero at 100 with that scope probably.
Also you’ll find at the upper end of travel shading appears and image starts to suffer.

That’s what I was worried about. Ty

 

[badassgunworks]

That’s what I was worried about. Ty

30 moa base will zero at 100 yards though

 

[Jon Conley]

30 moa base will zero at 100 yards though

I really wanted to go with 100 yards zero to make my Streloak Data as perfect as possible.
what’s the general consensus of everyone, do most people try to get sighted in at 100 or do you stretch it out to 200yd for the problem I’m having?

 

[Arcticshooter]

I just set up one of mine with the Era-Tac adjustable 0-20 MRAD mount (0-70 MOA). I went with the QD levers too.
Not cheap, but they did a beautiful job. I haven't had a chance to zero it yet, just waiting for a break in the work schedule.
With the 338LP you could really put those 70MOA to use.
Lastly, stretching your rifle WAY out there, while retaining the use of your 100yd zero is supposed to be pretty easy with this system.

 

[Jon Conley]

I just set up one of mine with the Era-Tac adjustable 0-20 MRAD mount (0-70 MOA). I went with the QD levers too.
Not cheap, but they did a beautiful job. I haven't had a chance to zero it yet, just waiting for a break in the work schedule.
With the 338LP you could really put those 70MOA to use.
Lastly, stretching your rifle WAY out there, while retaining the use of your 100yd zero is supposed to be pretty easy with this system.

Thanks..

 

[AZgeek]

Yup. The Era-Tac system works really well. Have one on my Barrett M82A1 and was able to get the full 120 MOA out of my ATACR scope. Again proper ring height (to take advantage its full 70 moa capability with your scope) is required.

 

[nutation]

I am a bit confused. With a 20 MOA mount, wouldn't the scope body start pointing more upwards, and you have to adjust your turrets downwards (towards the minimum), to leave you the maximum elevation adjustment to go UP? This would move the front lens of the scope further away from the barrel, wouldn't it? Relative to the front (objective) lens, the rear (ocular) lens would be tilted closer.

I may be wrong here, and if I am, square me away.

More elevation (whether from the base or from adjusting the turrets) angles the muzzle upwards relative to the line of sight. So, a canted base moves the objective closer to the barrel. For a 20 moa base, it's pretty easy to see the height difference between the front and rear of the base (front is lower).

 

[ELR researcher]

I’m trying to get setup for a mile and I’m not sure about my scope base.
The rifle‘s an AR-30 and came with a 15 min scope base. I’ve looked around and called Armalite, it doesn’t look like finding a different base will be easy. I’m trying to find out if the 15 minute base will work.
My scope is a Viper HST and it has 65 MOA in it.
Strelok says I need 227 clicks or 57 MOA. Am I thinking about this correctly? I need 57 MOA and I have 65 in the scope, so that gives me 32.5 mins of vertical plus the 15 mins in the base. That gives me 47.5 MOA and I'm left 10mins short if things ended up prefect..
Well I guess it depends on how many clicks I have left once I‘m sighted in. I’d like to sight in at 100 yd.
I’ve never shot past 1,000 yd so I’m just trying to get this right in my mind.

Thoughts?

AR-30 in 338 Lapua
300 gr Berger OTM @ 2880 fps
Vortex Viper HS-T 6-24

Jon - call Cameron at Murphy Precision. He already builds a 20 MOA base for the AR30 (https://www.murphyprecision.com/Products/Item/1140) and will likely be happy to build in whatever MOA you want. ERATAC adjustables are great (!) but expensive. These folks have the best prices I've found - https://www.newenglandcustomgun.com/products.php?cat=282

 

[Jon Conley]

Jon - call Cameron at Murphy Precision. He already builds a 20 MOA base for the AR30 (https://www.murphyprecision.com/Products/Item/1140) and will likely be happy to build in whatever MOA you want. ERATAC adjustables are great (!) but expensive. These folks have the best prices I've found - https://www.newenglandcustomgun.com/products.php?cat=282

Thank you so much.

 

[jasent]

Just shim and bed your current base. Done it tons of times. Never any troubles. Shim till your zeroed near bottom at zero. Then bed rail with those shims. Custom base. 60 moa is 1 degree of angle. So your not really changing much at all. I use aluminum flashing for shims

 

[Arcticshooter]

Out of curiosity, I checked the NECG website to see if they would have a better deal
for me on the next one.
They are listing the ERATAC model I just bought, for $5 more than EuroOptic sold it to
me for.

 

[ELR researcher]

Out of curiosity, I checked the NECG website to see if they would have a better deal
for me on the next one.
They are listing the ERATAC model I just bought, for $5 more than EuroOptic sold it to
me for.

The non-clamp is less, the QD is slightly more at NCGG.

Thanks for the tip though, just noticed that EO is selling models that are not even on the ERATAC site - VERY interestingly with 80-150 MOA and 25-45 MRAD adjustment ranges. I just called EO and they actually have some of those puppies in stock (some others not yet - depends on tube dia and sightline height). Say WOW!!! 150 MOA or 45 MRAD - of course, on top of whatever your scope has.

 

[Arcticshooter]

I picked up the QD 0-20 MRAD and it's proven to be solid so far, though I haven't played with the elevation cam yet.
I was impressed that they had the 25-45MRAD available. Holy crap, that's a lot of elevation.

 

[Steel head]

I picked up the QD 0-20 MRAD and it's proven to be solid so far, though I haven't played with the elevation cam yet.
I was impressed that they had the 25-45MRAD available. Holy crap, that's a lot of elevation.

Actually it’s not a lot of elevation.