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Old August 18, 2010, 01:20 AM   #1
Hoskins
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0 MOA, 20 MOA Bases/Scope Mounts????

Sigh...ok, got the Savage 10FP .308. Want to use this rifle for not only hunting, but also want to become a 1,000 yard shooter. I understand that a 20 MOA scope base is generally used for shooting at ranges from 600 to 1000 yards, however, can you still utilize it for firing at close ranges?

What I mean is, do you have enough depression in elevation using this base? I'm looking at getting a EGW 20 MOA mount. If I can't hit targets w/n 100 yds using the 20 MOA, then I don't want it. I'll go with a 0 MOA.

Thanks in advance & please excuse my ignorance to all of this. Though I am a Marine...I am not a sniper, so I don't have the knowledge on all the gear that goes into it....though I am confident in my marksmanship skills (fundamentals of marksmanship).
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Old August 18, 2010, 08:28 AM   #2
Jim Watson
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Depends on the scope.
Let's assume that you are on target at 100 yards with the scope in the center of its range of elevation adjustment on a level mount. Put a 20 moa base under it and come up 15 more moa and you are on at 1000. To check your load at 100, come back down 35 moa, 20 moa below center to counteract the tapered base.
So the question is, does your scope have at least 40 moa of elevation adjustment?

There is a Leupold VX III 8.5-25X on my Savage. It is cataloged to have 94 moa of adjustment and will therefore run from 100 to 1000 yards without any trouble. I use the tapered base to keep its long range setting close to center where the lenses are best.
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Old August 18, 2010, 09:54 AM   #3
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What JW said. Some scopes may only have 50moa total travel, while others are 100 plus moa. As you come close to the limit of your elevation adjustments you well have less windage adjustment.

My particular scope has 95moa adjustment, with a 20 moa mount I should have close to full windage adjustment available at 900-1000 yds.

I'm just getting into longer range shooting(400+) and it is full of challenges, very enjoyable.
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Old August 18, 2010, 10:24 AM   #4
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Quote:
PRACTICAL LONG-RANGE RIFLE SHOOTING - PART II: OPTICS

All Rights Reserved, written by Zak Smith

An inclined base with 20 MOA angle will shift the zero point in the scope further away from its top extent. For example, with the 60 MOA scope described before, instead of being zeroed around +30 MOA (its center), it would be zeroed at about 30 - 20 = 10 MOA up from bottom, and have about 30 + 20 = 50 MOA "up" elevation left.
I'm not familiar with the adjustment ranges of all available scopes. However it is hard to believe that a quality one, designed for long range shooting; would not have at least 60 total MOA of adjustment.

Tell us which brand scope you have and someone may be able to find its total MOA adjustment range.
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Old August 18, 2010, 10:51 AM   #5
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Hoskins,There are a couple different options here.First,if you are wanting to shoot long range,make sure the scope you would like to use has a decent amount of adjustment.
You can use a 20 moa rail or use a set of Burris Signature Zee rings,they have inserts that you can offset the scope 10,20,or 30moa.Plus these rings will not leave any ring marks on your scope.They are the only rings I use anymore.

I use Ken Farrell base rails,and Burris Zee rings on all of my long range Savage rifles,and also really like Sightron SIII scopes.They have 100moa of adjustment and are a very nice quality scope.
The clarity of the Sightron is right with the Swarovski I have on another rifle,for 1/3 of the price.

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Old August 18, 2010, 10:54 AM   #6
Hoskins
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Thanks gentlemen! Don't laugh too hard or think I'm not "TactiCool" enough but the brand & model scope I have is a Mueller 4x16x50 Tactical scope w/ the illuminated mil-dot reticle.

The "click"/ MOA is 1/8"...which I would prefer that it was broken down into 1/4" adjustments because there is (4) extra clicks (.5 MOA) between the #7 & 0 on the dial. That means that all my markings will be off by .5 MOA after one evolution on the dial, no problems...I'll just have to practice & get familiar with that.

I think that my scope has 60 MOA of adjustment. I just got it lastnight & am still getting familiar.

Additionally, why would the 20 MOA scope base have anything to do with windage? I thought that the raised base was to give you more elevation only?

TXHillbilly, thanks brother. I know that I am eventually going to have to invest in a better scope for all around better shooting at 1000 yds. I just got the rifle, a new Harris bipod, some ammo, & I wasn't going to take anymore $$$ out of the bank on a $600-$1000 scope. I think you got to start somewhere & 1000 yds shooting isnt just something you can do consistently as a noob.

I can iron sight shoot the M4/M16 at 500 yds on the Echo tgt (torso), but there is so much more that goes into the scope, wind calls beyond that range, elevation, angle, etc... etc... etc... I think if I can get good & consistent at 600-700 yds, then it would be time to bump up to working on 1000 yd shots. Thoughts from the experts on my way of thinking? I'm himbly seeking advice & wisdom.

Last edited by Hoskins; August 18, 2010 at 11:02 AM. Reason: TxHillbilly posted while I was replying to post.
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Old August 18, 2010, 12:38 PM   #7
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Hoskins-
Before you go buying, do some on-line shopping for a scope. Look for scopes that have 60 or more MOA of elevation adjustment. That's 30 MOA up, and 30 MOA down. Depending on your load, it takes about 35-40 MOA to go from your 100 yds zero to a 1000 yds zero. If your reticle is centered when zeroed at 100 yds, you cannot quite make it, and most will not be centered at 100 yds. As mentioned above, Burris rings with the offset inserts can do it, or you can go to a dedicated base. A 20 MOA base will take care of 1/2 of the needed travel, and still let you use the scope for closer range shooting.

Quote:
My particular scope has 95moa adjustment, with a 20 moa mount I should have close to full windage adjustment available at 900-1000 yds.
That's a lot of elevation adjustment, typical of a high magnification target scope. Most hunting scopes have little more than 1/2 that (45-60 MOA elevation adjustment travel). So make sure whatever you buy has enough adjustment.
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Old August 18, 2010, 12:49 PM   #8
Jim Watson
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Quote:
Additionally, why would the 20 MOA scope base have anything to do with windage?
Because the erector tube which makes internal adjustments is moving inside the cylindrical scope tube. Diagram to visualize: Draw a circle, mark it "up" and "down", "left" and "right" like scope adjustments. Make a mark in the center as though the scope were at mechanical zero. Now draw a line left to simulate allowing for a west wind. See how far you can go? Now make a mark near the bottom edge. See how much less travel you have sideways? That is why you need to be working near the center of the scope at long range, to have ample adjustment for windage.
The lenses are also sharper near the middle.
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Old August 18, 2010, 04:39 PM   #9
Txhillbilly
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There's nothing wrong with a Mueller scope.I had one on my 300WM until I came across the Swarovski PH that's on it now.
The Mueller now resides on one of my AR15's. For the price,Mueller makes an OK scope.
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Old August 19, 2010, 01:02 AM   #10
Hoskins
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So from what I'm gathering, it sounds like the 20 MOA mount is the way to go. Hopefully that will give me enough to reach out to 1000, but I don't know if the scope has enough MOA on it to reach out that far, guess I'll just have to do a little bit of math & a whole heck of alot of shooting to see just how far I can reach out.

Next question, should I zero at 100 yds or 200 yds for point of aim/point of impact or should I zero high at 100 yds so that I extend the max point blank range?
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Old August 19, 2010, 07:33 AM   #11
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I have an IOR 6-24x50 on my Remington 700P and it has about 50-60 MOA adjustment max. To be sure I could reach out to 1000yrds I bought a 30MOA base. My scope can hold a 100yrd zero on the 30MOA base but just barley, a few more clicks and I am bottomed out. You should be fine getting a 100yrd zero on a 20 MOA base, but if you only have 50-60MOA adjustment in your scope you might be stretching it to get a 1000yrd zero. I would buy a 20MOA base and get good at shooting mid to close range with your current scope. If you get good enough and take it out to a range that your scope can’t adjust to anymore, go buy a better scope with better glass and more MOA adjustment. If you are shooting 800+ yards you will probably want clearer glass than what you have.
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Old August 19, 2010, 07:59 AM   #12
Jim Watson
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Quote:
So from what I'm gathering, it sounds like the 20 MOA mount is the way to go. Hopefully that will give me enough to reach out to 1000, but I don't know if the scope has enough MOA on it to reach out that far, guess I'll just have to do a little bit of math & a whole heck of alot of shooting to see just how far I can reach out.
Mueller does not catalog the adjustment ranges of their scopes that I can find. You will just have to count clicks or graduations from top to bottom to see how much you have.

Quote:
Next question, should I zero at 100 yds or 200 yds for point of aim/point of impact or should I zero high at 100 yds so that I extend the max point blank range?
If you are target shooting, zero for the range you are shooting at. You will develop a chart of sight settings vs range by calculation and live fire.
If you are hunting or shooting targets at short unknown ranges, then apply the point blank calculation to your load and target size. Probably come out in the neighborhood of 200-250 yards.
If you are hunting at long unknown ranges, you have to estimate the range and apply the chart you worked up at known ranges. Lots of shooters have range cards taped to their gunstocks.
Mil dots or other reticle features can both estimate and allow for range if you want to do it that way.
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Old August 19, 2010, 09:16 AM   #13
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Quote:
Originally Posted by Txhillbilly
You can use a 20 moa rail or use a set of Burris Signature Zee rings,they have inserts that you can offset the scope 10,20,or 30moa.
I knew about the Zee rings for correcting off set issues but was unaware they offered that much incline. I'm going to look at that.


Quote:
Originally Posted by Hoskins
Thanks gentlemen! Don't laugh too hard or think I'm not "TactiCool" enough but the brand & model scope I have is a Mueller 4x16x50 Tactical scope w/ the illuminated mil-dot reticle.
Mueller makes a very good scope, hard to beat for the money. I've been using a Muller TAC II for several years and it's more scope than I can use now. I may upgrade but I need more time with the combination I have before I do that. I'm still trying to be proficient at 400-600 yds before I try anything longer.

Quote:
Originally Posted by Next question, should I zero at 100 yds or 200 yds for point of aim/point of impact or should I zero high at 100 yds so that I extend the max point blank range?
Next question, should I zero at 100 yds or 200 yds for point of aim/point of impact or should I zero high at 100 yds so that I extend the max point blank range?

I zero at 200yds with my .308/7.62's, with your scope centered and collimated to the barrel your POI and POA should intersect at 40yds and 200yds +/-.

I want enough incline on the mount so I have to dial the scope down 20-25moa from center to be on at 200yds. That should give me all the windage adjustment I need at 600-800 yds.
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Old August 20, 2010, 11:09 PM   #14
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From the same article series linked to before:
http://demigodllc.com/articles/pract...-shooting/?p=2
Quote:
I recommend using a 100-yard zero instead of a longer-distance zero for several reasons. First, any wind that is present will have a very small affect on the zero. Second, if you are "off" in distance by up to 10 or 15 yards, the effect on your zero will be minimal. For example, if you're actually shooting at 90 yards or 110 yards instead of 100 yards exactly, the difference in point of
impact will be less than a tenth of a minute. Lastly, 100 yards is so short a distance that if you travel up or down in altitude, or if the temperature changes dramatically, your primary zero will not be affected. Longer-distance zeros such as 500 yards will become invalid with large environmental changes such as those, because the air density will affect the point of impact. When running a 100-yard zero, the primary zero stays valid, and you just need to adjust your down-range dialed trajectory.
If you have a scope with external knobs, set the primary zero at 100. If you want a different "field zero", just dial the knob up-- that's why it's there.

If you do not have external knobs, then either zero at a distance to maximize your effective point blank distance, usually a 200 or 250 yard zero will work well; or, if you have a reticle with marks for elevation holdoff (such as mils or moa), then you can set a zero to make easiest use of those marks.
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Last edited by Zak Smith; August 20, 2010 at 11:14 PM.
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Old August 20, 2010, 11:13 PM   #15
Hoskins
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Thanks Zak, BTW, I'm reading your articles...& then going back & reading them again. I've got them favorited & also got shortcuts saved in a desktop folder I call Long Range shooting.

Your articles are great & I'm definately learning alot from them. I just finished Pratical shooting 2, will be moving to 3 tomorrow...& then starting back on one for a read read of all 3 articles again.
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Old August 21, 2010, 02:33 AM   #16
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I'll second the Burris Signature Zee rings. I have a Vortex Viper that has 64.5 MOA actual travel. Using the Zee rings with the 20MOA inserts gets me out to 1000 yds very well. Add to that the fact that you do not have to bed or lap the scope rings. You may want to consider the Viper. It is a very good scope for the money.
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