0 or 20moa base?

[kopcicle]

Not sure how the slant up and down would give you more adjustment left and right.

Measure a tube across the center and you get the full inside diameter.
Measure a tube across the bottom quarter of the tube and you get significantly less.
Scopes work the same way.

 

[Koda]

Windage left and right. With the 20 MOA base adds a slant to you scope allowing more elevation. Not sure how the slant up and down would give you more adjustment left and right. But I'm no sniper and am just getting into distances past 500 yards. So I'm also learning and love learning new things. I may be too simple minded. Haha.

I also prefer mils as that's what I'm familiar with from the military.

with a 20moa base your zero is using up elevation on the side of it thats not needed. So when you need to dial for drop you have more range of motion to get where you need before maxing out the range of elevation motion.

with a 0moa base you will be 20moa closer to the end of travel, in a round scope chassis, will limit your windage range of motion at the extreme end of the elevation travel.

 

[Member 53328]

Measure a tube across the center and you get the full inside diameter.
Measure a tube across the bottom quarter of the tube and you get significantly less.
Scopes work the same way.

Ahhh. I totally get what you're saying now. Thank you! I wasn't taking that into effect but that makes complete sense. I feel real dumb now. Haha.

 

[Koda]

Measure a tube across the center and you get the full inside diameter.
Measure a tube across the bottom quarter of the tube and you get significantly less.
Scopes work the same way.

yes, so them my question is does this mean a 20moa base is better for allowing more windage adjustments at longer ranges?

 

[P7M13]

when you start with two tubes that are perfectly centered (concentric) and tilt one in one direction you get less range of motion in the other direction due to the stationary tube being round.

That's the fallacy. They're not perfectly concentric. A scope with its crosshairs perfectly centered, mounted on a gun, will have a natural zero because of the angle that already exists between the rifle and scope. At least that has always been my understanding....

@P7M13
Of course all the above maths go out the window when I'm using the fine target dot and the 32x.
Then all the dope goes in the scope.

Weaver?

 

[kopcicle]

@1775usmc
When I'm not bubbleguming I'm here to serve. Not a problem and you're welcome.

 

[kopcicle]

yes, so them my question is does this mean a 20moa base is better for allowing more windage adjustments at longer ranges?

absophuckinglutely

 

[Koda]

That's the fallacy. They're not perfectly concentric. A scope with its crosshairs perfectly centered, mounted on a gun, will have a natural zero because of the angle that already exists between the rifle and scope.

I was referring to the mechanical range of motion from a factory new optically centered scope. I do realize that even with a 0moa base and a closer 100yd zero the scope will not be perfectly centered due to the height of the scope from the rifles bore.

 

[kopcicle]

That's the fallacy. They're not perfectly concentric. A scope with its crosshairs perfectly centered, mounted on a gun, will have a natural zero because of the angle that already exists between the rifle and scope. At least that has always been my understanding....

Weaver?

Malcolm

 

[Koda]

absophuckinglutely

excellent, so then this is the trade off from the theory of being closer to optically centered using a 0mao base being "better". It sounds to me like the 20moa base has the advantage?

 

[kopcicle]

excellent, so then this is the trade off from the theory of being closer to optically centered using a 0mao base being "better". It sounds to me like the 20moa base has the advantage?

Sure, as long as you can still make the 237 yard MPBR zero.
Note: I went back and edited that into the mess of data I posted. No one missed it ? hahaha

 

[ELRShooter]

I run 20 MOA rails on all my 1,000 yard guns and zero at 200, but generally I'm shooting 400+. Easier to stretch past 1,000 that way. Windage is generally not a problem. A 20mph cross wind can push a bullet 4 mils at 1,000, that's if it's 90 degrees which it generally isn't. Multiply mils by 3.6 to get MOA.

 

[kopcicle]

Once you gather your own ballistic data for bullet weight, velocity, and BC the rest of this is easy.
Not returning to a 100 yard zero buys you some room.
Having that 5" pipe out to 280 yards as a zero stop can be golden for a surprise or snap shot.
Use gundata.org to get close and then move on to a real G7 solver to get a better idea.
It's simple really, just play around with zero range until you're no more than 2.5" above line of sight and accept what the load gives you at 2.5" below line of sight.
Two of my mentors are members here as well as several service trained riflemen that know me.
None has stepped up to call me an ID10T , yet.

 

[TTSX]

My results with 20 MOA bases are that my zero before adjustment is wayyyy out there. My Barrett has a natural 800yard zero. Have to hold above the crosshairs if I'm shooting 500.

My Remington 700 was zeroed at 200, swapped to a 20 MOA one piece base and had to lower the elevation adjustment just to get a 500 yard zero.

I'm very, very sure you don't need a 20 MOA base

 

[kopcicle]

Multiply mils by 3.6 to get MOA.

^^^this

 

[Koda]

Sure, as long as you can still make the 237 yard MPBR zero.
Note: I went back and edited that into the mess of data I posted. No one missed it ? hahaha

why would you not be able to zero at whatever distance you want with a 20moa base?

 

[P7M13]

I was referring to the mechanical range of motion from a factory new optically centered scope. I do realize that even with a 0moa base and a closer 100yd zero the scope will not be perfectly centered due to the height of the scope from the rifles bore.

In my experience, it is pretty darned close to being centered. Otherwise, I'd have to dial the scope up 1.5 MOA to zero at 100.

As far as windage adjustment, I also do not agree with your assertion that you have reduced adjustment at the extremes. The reticle is a fixed, laser scribed plate inside the scope. While we think we are moving the reticle, we are actually moving the focal axis inside the scope, which is why parallax is so important. Otherwise, you would find mechanical restrictions on your travel as you move to the extremes. I have not found limits in travel while the other axis is at an extreme adjustment.
Also, typical of all my scopes, the horizontal travel extents are typically 1/2 the vertical travel.

[edit to add] This is my understanding and observations of scopes. It does pique my interest and I think I'll read up some more on it.

 

[Koda]

I have not found limits in travel while the other axis is at an extreme adjustment.
Also, typical of all my scopes, the horizontal travel extents are typically 1/2 the vertical travel.

isnt that finding a limit in travel?

 

[kopcicle]

why would you not be able to zero at whatever distance you want with a 20moa base?

Sure, but why give up a natural 5" MPBR?
At zero stop my .270 Win is zeroed at 225 for a 140rg at 2920 fps
I'm going to hit anything 5" in diameter with a dead hold out to 264 yards.
I do have a cheat sheet out to 400 yards where it's down 20 inches.
I have a 4x24x50 mounted but it rarely sees anything over 10x unless we're in dog town.

 

[Koda]

Sure, but why give up a natural 5" MPBR?
At zero stop my .270 Win is zeroed at 225 for a 140rg at 2920 fps
I'm going to hit anything 5" in diameter with a dead hold out to 264 yards.
I do have a cheat sheet out to 400 yards where it's down 20 inches.
I have a 4x24x50 mounted but it rarely sees anything over 10x unless we're in dog town.

Im not understanding why a 20moa base would not allow me to zero for a 5in MPBR.