Need help for a 100yds '0' w/ 40 MOA (rail+mount)
- Thread starter Kosmic
- Start date
- Location
- On a sand bar in the Atlantic Ocean.
Sounds more like a mortar than a rifle. 
How much wind are you shooting in that you need to dial for wind at your 100 yard zero? Any new scope that's worth owning has massive elevation travel. 80-120 MOA is the norm nowadays. Why not use it?
Keep in mind that he will be dialing up to the center of the scope for long range shots. So you are completely back asswords.
Zeroing is fine at 100. Doesn't matter how far you intend to shoot. I have never understood why guys feel the need to zero a dialing turreted optic at 2-300 yards when they could zero at 100.I would get it if they couldnt get the windage adjustment or get low enough elevation wise due to their set up, but your optic will end up in the same range internally regardless of the distance you zero at, 100 is an easier conformation and easy to spot your own bullet holes to slip your scales for a day of shooting. just my opinion.
I had a 40 MOA NF base on my 5R. With the 8-32X56 NXS scope at 100m I ran out of elevation and had to use the very top of the NPR1 reticle for the 100m zero. It's in a MDT TAC 21 chassis now with the built in 20MOA rail. Elevation adjustments are now all well within the limits of the .308 now, and able to use the centre of the cross hairs at closer ranges.
80moa travel is 40up 40down. Not 80/80. So no, 80moa travel is not massive amounts.
Windage is not a worry at 100yards but when you have a scope a few moa off the bottom of travel you may only have 5-8moa travel side to side to Center your scope over your barrel.
But i guess you knew all this and the simple geometry of two cylinders moving independently doesnt need to be explained.
80moa of internal travel with a 40 MOA base turns out to be lots of "up" travel.
I have a 40 moa base on my Savage 110BA. It has a Sightron SIII 6-24x50LRMOA. I don't need a zero stop because I am on the last turn on my turret. So I just bottom out the scope and go back up to "0". With that set up I have 39MOA right and 43moa left at my 100 yard zero.
I tested one more scope. This time a Nightforce NXS 5.5-22x56. I topped the scope out rather then loosening off my zero stop to be able to bottom it out. I ended up with 40moa right and 35moa left.
So I'm not sure what your talking about. Maybe something you heard on the internet.
Also I suck at geometry. It seems like my scopes suck at geometry as well. Maybe they didnt get the memo. Haha
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I don't need 40MOA. My question was, can I still zero at 100 yrds. I got my eyes on two scope mounts and they are both 20MOA.
How far am I shooting? not far, I'm still collecting the parts.
Ok, looks like it's a no-go. I'll wait and buy a 0MOA mount.
Thanks
You will be just fine with 40moa. I have a few set up on 40moa total mounts. This makes more sense in every way. You can still zero, you will be able to shoot further without holding over and you will have more windage adjustment when you acually need it.
The worse the ballistics are the more MOA you going to want. Shooting 308 out to 1200 or more that 40 moa is nice to have, can still zero at 100 so why not. Heck my 338LM has 50MOA between the mount and rail and I can still zero at 100 so why not?
Wow... these guys can be vicious... The answer to your simple question is yes (most likely, depending a little on the tolerances that your set up were built to).
The math: Your scope has 29 mils of internal travel. Which comes to 98 (ish) moa. So more than 45/45 up/down. So you should have more than 5 minutes to deal with any tolerance issues (and I haven't accounted for your particular sight height. But that itself is only a factor at 100 to 200 m... and it's only a minute or two.
As far as the... I don't even know how to put it... "moral" reasons of installing a 40 moa base? Or trying to avoid looking "tacti-cool"... or not trying to look like too much of a poser at the range? I guess? (really guys, come on, give some actual reasons behind the "help" that you give).
This is the best line that has been said so far.
"Zeroing" a rifle doesn't change the outside geometry of your rifle. It's not like you're doing that work to get your reticle on target at some distance then pressing a magic zero button that then centers your erector in the tube of the scope while keeping the reticle on target. No, no matter what you do to the aesthetics of your turrets (that's all that taking the caps off does) your mechanism will be in the same spot.
Now there are other relevant factors... Maybe the 40 base will raise your eye box too high for you to get a comfortable cheek weld? Another often overlooked factor is that you always want to be using the center of your glass for your most frequent shots. All lenses have some form of distortion, and the center of the lens is where you're going to have the most crisp, clear and true picture. To that extent... maybe you don't ever plan on using a full 80 moa for a shot. But even if you're going to go as far as needing 30 - 50 moa... well then, the 40 moa base will mean you'll be using the center of your glass for those shots.
So yes, it's a decision... but don't listen to anyone that's going to call you tacti-cool.
duncansuds
CGN frequent flyer
- Location
- Weyburn, SK
Well said. I had forgotten to menTion that using a 40 Moa base will help give maximum windage adjustments when putting your shot out to 1000+ yards. The way I set my .308 up was to have full windage availability between 800 and 1400 meters.... Where it counts.
I used to zero all my rifles at 200m and was considering zeroing my hunting rifles closer to 300 optimizing point blank range. Then I bought the Brian Litz Applied Ballistics DVD. My rifles will now all be getting zeroed at 100m. His reasoning and it makes sense to me is your 100m zero is less affected by external factors ie pressure and humidity and errors in range (ie 100m vs 100yards). Basically 100m zero at sea level for example will still be a 100m zero at 5000ft. This gives you a better base when dialling for range and reduces error. I put as much MOA as I can in my base and still allow me to zero at 100.
