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View Full Version : Anyone have this setup: model 12 F, 30" barrel w/ NF 12-42x56 scope?



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redmenter
05-29-2016, 10:12 PM
Hello,
so recently got my set up out to some 1000yrd shooting. Well to my surprise I ran out of adj at 900 yards? Wtf? Using a 20moa base, and yes triple checked I do have base on correct! Ha. Just trying to see if anyone with similar setup could lend some advice. After all I read I hardly saw anyone needing to use 40moa base ? I zero,d it at 200,but I notice that
At 200 I'm already using about 40% of my adj so only 60% of adj left. Which maybe is how it is. Again hoping if someone with similar can shed some light.
Thanks!

Texas10
05-29-2016, 10:19 PM
What caliber, bullet, velocity, twist and BC?

Bill C
05-29-2016, 10:42 PM
Did you put your base on backwards? Haha

Bill

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Robinhood
05-29-2016, 10:51 PM
This ought to be good. :p

redmenter
05-29-2016, 10:52 PM
That's first thing I thought , base bakazzwards!! But amazingly I had it correct!! Ha. High end in bak low end in front. It's a 6mmbr. Just using some store bought Papua 105gr scenario ammo. accuracy been perfect at 1,2,3,4,6,7,900 yards. Using ballistic App, made adjustment accordingly and smack dab on! So no issues.
Again I realize there's things I can do to add more adj to it. 40 moa base, Burris xtr signature Rings, etc. I just feel like my current set up should be more thAn sufficient to have enough adj out to 1000???

Robinhood
05-29-2016, 11:29 PM
200 yd zero the come up is about 10 mils on that ammo. .472 BC and 2789 MV

redmenter
05-30-2016, 12:32 AM
Hmm. Ok there could be something to that. ? My ballistic progrM has some pre programmed loads, including the scenar 105 I wAs using. So I picked that and just now looking it over I see it had the BC at .236. So if you change thT to .472 as u said, then I would have enough adj for 1000yds? Huge difference?? U using g7 or g1 ? That being said, as I stated I was hitting all the steel down range out to 900? So that still makes me think the adj I was doing must hve been close with the BC I was using verse the one you came up with?
and also the ones I reloaded, using the Berger 105 vid target, using Berger website shows the BC At .265 which would then once again leave me without enough adj on the scope? I didn't get around the shoot any of those loads yet.
But I totally appreciTe your help and thoughts!!!
thanks

Anschutz
05-30-2016, 01:32 AM
That is odd. Have you checked the torque on your base? I know it sounds trivial but every little thing makes a difference that far out.

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m12lrs
05-30-2016, 06:28 AM
12-42 benchrest has 40 moa of.vertical adjustment

With a 20 moa base you should see that you have used up almost all of your vertical down adjustment on a 100 yards zero leaving you close to 40 moa up.

With a 40 moa base you won't even be able to zero at 100 yards

redmenter
05-30-2016, 08:20 AM
Thanks again for the input guys!!! The last post about the total moa scope has. This is where I feel like the issue lies, between scope and the 20 moa base, when I am shooting at 100yds I should be much closer to the down adj bottomed? But to simplify ( for my sake) the scope can make 7 full turns of the dial from bottom to top, and when I am dead on at 100 yards I am already about 3 full turns up from bottom, leaving me only 4 turns of adj left. Again I realize I am simplifying the process. But I am just trying to somehow explain where Or why I feel like something isn't right? It just seems like I should be that far off the bottom already at 100? But that's just what I think.
Thanks.

Alleycat72
05-30-2016, 09:19 AM
Your barrel isn't straight or it's not in line with the action. The barrels used to be hand straightened at the factory. You should be two or three moa from bottoming out with a 100 yard zero.

jim_k
05-30-2016, 10:24 AM
Your barrel isn't straight or it's not in line with the action. The barrels used to be hand straightened at the factory. You should be two or three moa from bottoming out with a 100 yard zero.

I actually have the same set-up, with the Benchrest NF and mildot reticle. I can get up to about 800 yards, but run out of elevation, and I also have the 20 MOA base. Option #1: Ken Farrell base, 40 MOA. Option #2: Turn the scope magnification down to about 24X, and use the proper mildot to get the barrel pointed high enough to hit the target. (This option may not work with a FFP reticle, but the NF Benchrest is SFP. At 42X, I don't have enough mildots to get sufficient elevation, and turning down the magnification increases the available adjustment with a SFP reticle.) You can verify that it is a bent barrel by removing the bolt, and sighting down the bore, with the rifle firmly set on the bags. Sight your scope at a target, and look down the bore to see where the bore appears to be pointed. (This is bore-sighting the old way, which I have done for many years, when mounting a scope, so as to know where the first shot will go.) On straight barrels, the sights will be aligned with the bore, and the bore will appear to be pointed slightly high on the target. That is proper, and of course it is a result of the bullet drop at the range you are sighting. Even at 100 yards, the barrel will appear to point slightly high of the impact point, and this is not difficult to appreciate. If the alignment of the barrel to the action is not correct, which I have never actually seen, I think the sights and bore should "agree" with each other. However, on a rifle which has been sighted in to hit the target, if the barrel is bent, the APPARENT bore-sighting point will be way off from where the crosshairs are aiming. I'd rather have a bent barrel than a poorly aligned action. If the barrel is accurate, and mine is plenty accurate, the factory will not replace it, so choose from the options above. Of course, the ultimate correction is to replace the barrel, but I'm too cheap for that, so I chose Option #2.

redmenter
05-30-2016, 10:50 AM
Wow,thanks Jim K for the insight! I guess at some point I could take barrel in to check it? And could there also be an option 3 and 4? #3 is using the Burris xtr sig rings with those inserts for xtra moa adjustment? And then option 4 go get the NF nsx with zero stop! Ha.
I do appreciate all the help. I am starting to accept that I did ( miraculously ) mount, tighten,torque,cant, align, everything correctly. The gun shoots awesome groups on at 1,2,300 yards at the range. It's a tack driver!! Super consistent, so any bent barrel or so forth is having no effect on that. So maybe those Burris rings will take care of it and I can turn blind eye to root cause? I don't see any other simple fix?!?!?

But one last bit of my 2 cents and 3rd grade math education.......in scope mounting 101, they say when u zero at 100 yards, scope is built to usually be in the middle of its total adjustment? So if I have 40 total moa, at 100 yards zero,d I have 20 moa each way of adjustment. Then I add a 20 moa base, now, theoretically when zero,d at 100, I should be almost bottomed out with about all 40moa of my adjustment left!?!?
ThAnks

Robinhood
05-30-2016, 11:23 AM
Redmenter, The load data I got was from the Lapua web page and they only list G1. If you have a 100 yd zero what is your come up at 900 yds

m12lrs
05-30-2016, 11:35 AM
Wow,thanks Jim K for the insight! I guess at some point I could take barrel in to check it? And could there also be an option 3 and 4? #3 is using the Burris xtr sig rings with those inserts for xtra moa adjustment? And then option 4 go get the NF nsx with zero stop! Ha.
I do appreciate all the help. I am starting to accept that I did ( miraculously ) mount, tighten,torque,cant, align, everything correctly. The gun shoots awesome groups on at 1,2,300 yards at the range. It's a tack driver!! Super consistent, so any bent barrel or so forth is having no effect on that. So maybe those Burris rings will take care of it and I can turn blind eye to root cause? I don't see any other simple fix?!?!?

But one last bit of my 2 cents and 3rd grade math education.......in scope mounting 101, they say when u zero at 100 yards, scope is built to usually be in the middle of its total adjustment? So if I have 40 total moa, at 100 yards zero,d I have 20 moa each way of adjustment. Then I add a 20 moa base, now, theoretically when zero,d at 100, I should be almost bottomed out with about all 40moa of my adjustment left!?!?
ThAnks

Do you find you had to adjust the windage well off center? I would suspect if you had a bent barrel it.would effect more than the vertical.

I suspect you don't have a true 20 moa base.

Robinhood
05-30-2016, 11:39 AM
Using Berger and Hornady Ballistic Calculators I came up with the same thing in G1. 10 mils or 34 MOA. that should get you on paper. 10 MPH crosswind will move you about 70 inches or 2 mil.

If you have the NXS you are looking at 12 mill total internal elevation adjustment. Many long range scopes have considerably more that that. Nice scope but you will need more slope on your base, cut and dry. Just for grins cut a piece of pop can into a shim, use double thickness under the rear of the base. Go back and re-zero at 200.

redmenter
05-30-2016, 12:15 PM
My base is about .35" from one end to the other. Or close to that. Hard to measure on gun. But my math says that is actually correct for a 20moa base. So that's is gooD
My chart shows I need to come up about 25 moa at 900 yards, when zero,d at 100.

Robinhood
05-30-2016, 12:32 PM
My base is about .35" from one end to the other.

Can you explain this. Is it .35 on both ends or there is a difference of .35 from end to end? (I am hoping it is more like .035)
According to one of your post you are using Lapua factory ammo. You also stated that you had a 200 yrd zero. It looks like our numbers are comparable. Your bullet drops another 90 inches between 90 inches between 900 and 1000. thats 9 more MOA. Take your 25 at 900 and ad 9 to it and you get 34 moa. Looks like we are on the same page again. You need more slope on your base.

redmenter
05-30-2016, 12:39 PM
Ha .035. My bad. It specs out according to where it should be.
Whole heartily agree I need more slope. Just back to original question, just seems odd with this set up I wouldn't have enough to shoot at 1000?!?!? Since that's the whole point of this rifle and scope from the factory?!?!? Ha.
But as Jim k said he has similar rig and maxes out around 800yrds. So who FU?!$&@ knows!!!! Haha.

Robinhood
05-30-2016, 12:53 PM
There is data here that will tell you why.
http://nightforceoptics.com/nxs/12-42x56