Scope base NXS12-42 .125moa for 1000yd

[dsbur]

Imagine my surprise when I first shot beyond 800yds recently and found that my Nightforce scope ran out of adjustment with my 20MOA base. The .125MOA click Nightforce has a little over 40MOA of adjustment total.

A little guidance, I presume a 40MOA base is in order? Yes, 4.5MOA holdover gets me to 900yds etc. but don't want to go down that road. I don't envision shooting beyond 1000yds. F/TR wanabee. It's only a SA Rem 700 action 5R with a re-stock and Jewell but sure is fun so far. Barrel and blueprint eventually.

Love the scope, it really improved my shooting. Basically a DCM Garand/Springfield guy from many years ago who needs glass now and is reaching out beyond 600yds.

Curious as to what folks are using and are happy with base-wise to improve such a situation.

Thanks in advance-

 

[Immike]

Take the scope back to your 100 yrd zero and count the min up and how many down. You can see how much room you have to change the base if needed.

 

[XTR]

You shouldn't have been surprised. I ran both my NXS and my BR on my Remington action with 30MOA bases. (20MOA bases from Badger wouldn't get there, Badger is pretty reliable parts maker)

Go back to your 100 yard zero, to get to 1000 yards you will need well over 30MOA with most bullets. If you are loading 175 SMKs out of a 26" barrel you're probably going to need over 36MOA to get to 1000. For an F-TR rifle there are a lot of guys who can't get a 100 yard zero. With either of my NF scopes on my new Defiance action with the rail on it (supposed to be a 30) I bottom out at 300 yards, but I do basic load work at 200 so I just aim at low dots and look at groups, then I do the rest of my work at 300 and 600 to dial my loads. The rest of the yr the scope lives with my 1000 yard come up which may as well be a zero.

From 800 to 900 you will need about 5MOA, and you will need about another 5MOA from 900 to 1000. If you could get on the point of aim at 800 but ran out after that going to 900 then going from a 20MOA to a 30MOA should get you on out to 1000. If you were low at 800, but close you will need a 35MOA rail. The only problem with that is that you are going to be all the way at the end of the erector adjustment springs. Your scope is happier closer to the middle.

If this is going to be a long range rifle you may have to sacrifice the ability to get a 100 yard zero.

 

[ARIZONA_F_CLASS]

I have 3 FTR 308's. 2 WITH 12-42 NXS on the 1000 yard rifles. I have 40 MOA bases on them. I'm an inch high @ 300 yards with the scope bottomed out. That will depend on your load. As to how close you will be to a 0 @ 300 yards

 

[dsbur]

Hmmm...just checked it-

25.5MOA of adjustment from my 100yd zero. Guess I better check the bill of sale on that "20MOA" base-

Yes, 175SMK's behind 45gr RL15, Lapua Palma brass and CCI450's is barely getting me 2650fps on a 26"bbl so after 800yds she's falling off pretty quick I'm sure although I was printing nicely at 900yds with holdover so I'm not ready to give up yet. JBM is telling me it's getting slow out there also and I need about 38MOA to reach 1000yd.

Wonder how the heck you measure a one-piece base to check MOA

Never heard of a 35MOA base, guess I better do some homework.

 

[Immike]

It's all together possible that the base is not what it supposed to be. It should be taller on the back end. If not then you have a straight base.
40 min scope on 20 min base should = 40 min adjustment.

 

[XTR]

It's all together possible that the base is not what it supposed to be. It should be taller on the back end. If not then you have a straight base.
40 min scope on 20 min base should = 40 min adjustment.

No, not necessarily. His experience pretty much mirrors mine.

You are assuming that you get an erector centered every time, you get the erector centered where ever the person assembling the scope put it. The people assembling these scopes in Japan don't shoot. They probably don't know how it effects performance one way or the other. You are also assuming that there is 0 MOA relative to the bore between the front and rear of a Remington action. Another possibility is that NF realizes that every Tacticool shooter out there puts on a 20 MOA base. If they don't center the erector above that then they run the risk of getting complaints that you can't get a 100 yard zero on a 20 MOA base.

Read my posts. Both my 32BR and my 42NXS needed 30 MOA bases to work to 1000 yards on my Remington action, and both held close to zero (i.e., needed a 10 MOA adjustment) when moved to another Remington actions with a 20 MOA base from other manufacturers. With a 30MOA base my 32BR zeros at 100 yards 6 MOA from the bottom, and my 42 NXS zeroed at 100 yards 4 MOA off of the bottom. One of the things I have to remember to do when I move one of my target scoped onto a rifle to do load work is to remember to dial down 10MOA and come back up 1.5 to shoot at 200. Works every time if I remember.

My new Defiance action would have worked with a 20MOA base, but it's running a 30; but that is a whole different action geometry, the base had to be custom made.

I've posted this before to give people a heads up on what they will need so they don't show up at their first match aiming at a tree on the berm to get on the target because their NF ran out of adjustment

 

[Turbulent Turtle]

The question was asked: how do you measure the angle of a canted rail?

Trigonometry, of course. However, rather than explaining about arctangents and doing some fun but perhaps confusing calculations, I point the reader to this website:

http://www.carbidedepot.com/formulas-trigright.asp

Now, the way I would do this is as follows.

1- We are going after an angle here so we need at least two lengths. Look at the site, then measure side B. That's the length of the bottom of the rail. You then measure side A by measuring the front and rear heights and subtracting the former from the latter.

2- Once you have the values, in decimal inches, key them in and hit calculate. Angle A will be a decimal value from 100. There are 60 minutes in an angle so you need to multiply the value of angle A by 60 to get the MOA value.

Please not that you must be exceedingly precise in your measurements, for example a 4 inch rail with a 20 MOA cant will have a difference between front and rear of only 0.023 inch.

 

[dragman]

This is why I love burris Signature rings. Put a 20MOA base on it then add up to 20 more with the rings. makes life easy and have always had great luck with them.

 

[Turbulent Turtle]

+1 Burris Signature rings are the best.

 

[dsbur]

Wow, information overload, thanks!

The action has 2 levels fore/aft so the trigonometry will be hard to figure out i.e. it's not a level playing field so to speak. The rear of the base is in fact taller but the rear of the action is shorter.

Regardless, looks like I need another 10-15moa to stay in the game, either with the Signatures or another base. Kinda like my XTR's but Signatures seem to have a good rep.

 

[CatShooter]

Wow, information overload, thanks!

The action has 2 levels fore/aft so the trigonometry will be hard to figure out i.e. it's not a level playing field so to speak. The rear of the base is in fact taller but the rear of the action is shorter.

Regardless, looks like I need another 10-15moa to stay in the game, either with the Signatures or another base. Kinda like my XTR's but Signatures seem to have a good rep.

I use Signature Zee's on 90% of my rifles (the others have Unertls).

Signatures are such an easy solution to all of this poo-poo, it is a waste of time to do it any other way... and they won't make up your scope tubes either.

 

[Steve Blair]

I use 20 MOA bases on four .308 F-TR rifles and have no problem shooting at 1000 yards. I've shot everything from 155.5 Fullbore to 230 Hybrids. Scopes used are both NXS 12-42 and Sightron 10-50. They all comfortably zero at 100 yards for load development and out to 1000 for matches.

 

[Keith Glasscock]

I use 20 MOA bases on four .308 F-TR rifles and have no problem shooting at 1000 yards. I've shot everything from 155.5 Fullbore to 230 Hybrids. Scopes used are both NXS 12-42 and Sightron 10-50. They all comfortably zero at 100 yards for load development and out to 1000 for matches.

Ditto here.. Considering the amount of travel in an NXS, I'd recommend that the OP take a good look at the bases he has on. There is something wrong. I've actually seen a 20MOA base installed backward - not likely the case on this one...

 

[dsbur]

Busdriver-

Sure miss you stirring the pot down here, TCGC just doesn't seem interested in short/mid-course F/TR since you left.

Am checking my local cronies at Clark Rifles to compare 20MOA bases, at this point I strongly suspect it's a straight base and not what I ordered originally.

 

[Dos XX]

The rear of the base is in fact taller but the rear of the action is shorter.

Thus offsetting some or all or more than all of the 20 moa base.

 

[Steve Blair]

A correctly made 20 MOA base is relative to the action axis.

 

[Gman]

It's all together possible that the base is not what it supposed to be. It should be taller on the back end. If not then you have a straight base.
40 min scope on 20 min base should = 40 min adjustment.

No, not necessarily. His experience pretty much mirrors mine.

You are assuming that you get an erector centered every time, you get the erector centered where ever the person assembling the scope put it. The people assembling these scopes in Japan don't shoot. They probably don't know how it effects performance one way or the other. You are also assuming that there is 0 MOA relative to the bore between the front and rear of a Remington action. Another possibility is that NF realizes that every Tacticool shooter out there puts on a 20 MOA base. If they don't center the erector above that then they run the risk of getting complaints that you can't get a 100 yard zero on a 20 MOA base.

Read my posts. Both my 32BR and my 42NXS needed 30 MOA bases to work to 1000 yards on my Remington action, and both held close to zero (i.e., needed a 10 MOA adjustment) when moved to another Remington actions with a 20 MOA base from other manufacturers. With a 30MOA base my 32BR zeros at 100 yards 6 MOA from the bottom, and my 42 NXS zeroed at 100 yards 4 MOA off of the bottom. One of the things I have to remember to do when I move one of my target scoped onto a rifle to do load work is to remember to dial down 10MOA and come back up 1.5 to shoot at 200. Works every time if I remember.

My new Defiance action would have worked with a 20MOA base, but it's running a 30; but that is a whole different action geometry, the base had to be custom made.

I've posted this before to give people a heads up on what they will need so they don't show up at their first match aiming at a tree on the berm to get on the target because their NF ran out of adjustment

Nightforce scopes are assembled in Orofino, Idaho. The scope tubes are made in Japan.

 

[MarkS]

dsbur,

You need 10 to 20 moa. I like the Burris Sig. But one thing you can do on you existing rings, is add a quick dry epoxy to make your needed moa. I use JB quick 5 min set. Put the epoxy in the bottom of the both ring, at little more in the back ring. Put some oil on the scope so it will release. Push the scope into the rings, leaving the back ring thicker, let the epoxy get firm , but not hard. pull the scope and trim with a knife. Leonard Baity did this on a few long range gun for me.

One more thing you can do, is add shims under the back rings. I use wet/ dry sand paper cut to fit the back ring. I had 3 peaces under my back ring on my BAT 6BRX, and shot 3 IBS records in 600 yds BR, with this set up.

I buy the Burris Zee rings, and Weaver type bases, for new stuff.

Mark Schronce

 

[billshehane]

A 20 MOA base should be all you need. Mike the back and the front of that base and there should be about .040 higher in the rear than the front to give you the 20MOA you need.
You DO NOT need a 40MOA base. A true 20MOA Base is just fine to get out to 1000.

Bill Shehane