Reply With Quoteyour scope will not be optically centered with the 20 MOA base.
Is there a disadvantage to 20 moa bases if you are only shooting close range and never really need them?
I ask because it seems to me you might as well get 20moa "just in case".
Yes? No?
your scope will not be optically centered with the 20 MOA base.
"And you shall know the truth, and the truth shall make you free.” John 8:32 (New King James Version)
Other than that? I mean, if you shoot long and short range, it's not centered much of the time, anyhow, right?
I would guess most scopes aren't optically centered when zeroed, 20MOA base or otherwise. It's a valid point to consider, but working with a limited amount of adjustment and dialing correction for multiple distances you have to make do.
If for example, one was to never shoot past 500 yards, then one could shim a 0 MOA rail at the rear to an intermediate value like 10MOA or shim a 20MOA rail at the front to reduce it to 10MOA. But if one does that, one should use some bedding compound between rail and action and tighten the rail screws very gently until the bedding compound has set up. Thats the way people did it prior to there being tilted rails in the first place.
It is a question of how much movement the scope has. Many Nikons only have 40MOA of travel, so if you put it on a 20MOA you might not be able to zero it without shimming. Conversely, on a 0MOA rail you may not be able to dial up enough, depending on the cartridge.
Since we know the bullet is dropping from when it leaves the muzzle, it seems stupid to sacrifice half of your turret movement by having the scope parallel to the bore, unless it will only ever be shot out to 300-400 yards. There certainly are many people out there that fit this category and some that may top out at 160 yards or thereabouts (do not own a rangefinder). But if you plan to shoot 600 or beyond, you certainly want an inclined rail.
Thanks, guys.
Wes, I guess I was thinking what you are saying. But I did not know if there was something I don't "get".
My general rule of thumb is that if I am going to shoot 800 and under I go 0 MOA, my 308 has a 0 MOA base. If Im going to shoot past 800 then I go 20 MOA. Even if I dont shoot that far that often. I just gives the scope that much more elevation to adjust. The nice thing with the 6.5-47 Lapua that I just finished for my son with the 20 MOA base on it, the elevation knob is completely bottomed out for a 100 yard zero. Perfect zero stop.
MOAON AABE
I think I would have liked to try a 20 moa just in case... I ordered a couple 20 MOA EGW's from a couple different places and they keep getting back-ordered. Finally I ordered 0 moa's just to get them. I was also concerned the 20 moa's would not be able to get me down to 100 yds. I 'spose if it worked out just right, like Ryan's did, that would be great, but don't want to wait much longer to find out... I have two different rifles that need to be scoped, and I haven't decided on which scopes to use, either. I am thinking about getting a Weaver t-36 for 6BR and a variable 4-16 for the 20" .308 off of a Hog Hunter. Money is now beyond "tight" as I have a lot of different projects going.
That's a pretty good standard to hold. If you have no intention of taking your rifle out past 800, there's really no need for a 20moa base. Unless you're a mall ninja, or "tacticool", of course.Originally Posted by RyanG
Originally Posted by keeki
Guess it doesn't really matter. If ya cant afford $15, you won't be buying much anyways
Well, I would LIKE to be ABLE to shoot out to 1,000 if given the opportunity. Realistically, I probably won't though.
On the other hand, I heard the local mall was hiring... :)
I currently have 2 short action 20 MOA bases on backorder from SWFA. I called them today and they said that they were expecting a shipment of the EGW bases any day now...
Ryan
They were one of the places I gave up on. Oh well.
Midway had the EGW 20moa in stock last night when I ordered it, but that was a LA model.
Originally Posted by keeki
Guess it doesn't really matter. If ya cant afford $15, you won't be buying much anyways
I think it really depends on the scope. I have an older bushnell elite 3200 that only has 24 MOA. With a zero base I can only get to a little passed 500. Would it help to put a ramp on it? No! Why? Because it doesn't have adjustable turrets. On the other hand I have a leupold that has 64 MOA and without a ramp I can still get to 1000. It also doesn't have adjustable turrets. Now I do have two rifles that the turrets are uncapped and have a lot of adjustment but both have ramped rails and wouldn't have them any other way. I also have a rifle with a bushnell that has , I think, 120 MOA and it doesn't have a ramp. A problem I think that can happen is when you try to stretch out a rifle without a ramped rail you tend to work the scope in its outer limits of adjustments and this may cause more room for error. Personally I would want a scope to be more centered at a longer range an then be dialed down to a (less optimal) setting at a closer range like 100 or 200 yds. Probably doesn't make much sense, but that the way I see it.
Actually, that does make sense, assuming you can get the accuracy at 100 you want at the outer edge, saving the best of the lens for the more difficult distances.
I don't know what I am going to do b/c I am in a holding pattern waiting for a scope I bought used to ship and rail mounts so I can at least TRY to mount something... I have a variety of scopes avail. Sure would like to stumble across a Weaver t-36 owned by some old shooter's widow. You know the kind... the ones that were told their guns and optics cost about a third what they really did!
What do you mean not optically centered? That doesnt make sense to me.
let's just say you do a lot of 1000 yard target shooting so you need your scope as close to optically centered as possible to take full advantage of your windage adjustments. optically centered means you are as near to centered with your adjustments in other words have the same amount of adjustment no matter which way you turn your knobs as you can possibly get. You just have to decide what most of your shooting will be it's just an educated un educated guess a lot of times unless you're gonna hunt at extreme ranges anything under 500 yards the average decent scope doesn't need a canted base .
"And you shall know the truth, and the truth shall make you free.” John 8:32 (New King James Version)
Wouldnt that be considered "mechanically centered".
I always understood optically centered to mean you are using the center of the lens, which is normally the higher quality of view. The edge of a lens is not as "true" optically because the purpose of a lens is to bend light, but doing so distorts the image the further you get from the center of the lenss. So, the closer you move to the edge of the lenses, the less precise the image is, especially with lower quality lenses.
Or something like that. :)
Last edited by foxx; 04-12-2014 at 09:41 AM.
Thats what I was saying. When you cant your scope you are not changing your optics, you are just changing the angle. When you use a 20 moa base you still look through the center line of your optics, you are just changing the range of your reticle. Therefore you are changing the mechanical center of your optics. Your view in your glass wont change.
You may be right, bflee. But if so, Burris' claim to promote their Z-rings is non-sense (I don't think it is, though). They say you should first center your reticle mechanically, then use their adjustable rings to aim your scope as close as possible before making the final adjustments with the scopes adjustable reticle. Their reasoning is this allows you to use the best part of your lens for aiming, or whatever. If I understand them correctly, they are suggesting the angle of the mount affects what part of the lens you use.
I thought the reason I would want a cant is to allow me to use a greater portion of the scope's adjustment range, rather than just the lower part. i.e. with the cant, the scope points downward, forcing me to use the upper part of the its adjustments for close range. Normally, that part is "wasted" if mounted parallel to the bore. When I do so, I am utilizing the outer edge of the lens. Ideally, I want the scope mounted so I am using the best part of the lens (the center) at the distance I most normally shoot, but that is not possible if I shoot at all ranges, so I must compromise somewhere. The question becomes, where is image quality most critical.
Right?
Your reticle will not move enough to get you out of the "center" of your optic. You will notice no difference in your glass, just your adjustment range. If you can still zero at your shortest range you have lost nothing.
I don't know if that is correct or not, I guess. I thought when you moved your reticle to extremes, you were moving it outside the center of the lens.
Maybe not.
Is there anyone here that knows for certain?
Do you ever look into your scope after adjustments and the horizontal center reticle looks like it is anywhere but center? If you do you need a new scope! I make lenses for a living. Trust me, it is moving, but not enough to get you too far off center.
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