F T/R Competition Elevation Issues

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Minuteman
Mar 29, 2011
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Newbie here. I purchased a used Savage F/TR in .308 last Christmas so that i could stop sitting on the sidelines and start participating a bit. It came with a NF 20 MOA rail already installed. I borrowed a NF scope (can't remember exact model) from a good friend and zeroed everything in at 300 shooting 155's with 4895 powder (nope, don't remember the load). I noticed when i started adding up the amount of elevation that i would need to shoot at 1,000, I didn't think I had enough left so I added a 0.015" shim under the back of the rail and went to the range. With the 20 moa rail and 0.015" shim, i was able to shoot at 1000 but only had about another 1 - moa of elevation adjustment left. I purchased a new NF 15 X 55 Competition scope to replaced the borrowed one and replaced the 0.015" shim with a 0.010" shim and went to the 1000 yard line. I ran out of elevation. Aiming at center of the target, i was shooting beneath it. I ended up finding a clump of grass on the bank about 2' above the target which would allow me to have about 2 moa of elevation adjustment left in the scope. Any ideas as to why with two different scopes, i can't seem to get enough elevation to reach out to 1,000? What area do I need to look into next? Barrel issues possibly? On the second time, I was shooting 185 Berger Juggernaut's borrowed from another shooter who was shooting Palma that day with the same load. And thanks for everyone's replies up front. This website has been a blessing to newbies such as myself and i hope to one day know enough to help pay back to others. Oh, and regardles of the issues, i'm having a blast.
 
There are a couple of possible reasons. My Remington 700 action both my 42NXS and my 32BR need a 30MOA rail to get to 1000. My Defiance Rebel action only needs a 20MOA rail, the top of the action has a different angle than a R700.

It has to do with where they center the erector on the scope, every scope is not centered in the same place, and as you don't remember the model of the borrowed NF it may have had more elevation on the erector. The travel varies with the model, and in some cases it varies a hell of a lot.. You should probably break down and get a 30 MOA rail and you'll be fine.
 
There are a couple of possible reasons. My Remington 700 action both my 42NXS and my 32BR need a 30MOA rail to get to 1000. My Defiance Rebel action only needs a 20MOA rail, the top of the action has a different angle than a R700.

It has to do with where they center the erector on the scope, every scope is not centered in the same place, and as you don't remember the model of the borrowed NF it may have had more elevation on the erector. The travel varies with the model, and in some cases it varies a hell of a lot.. You should probably break down and get a 30 MOA rail and you'll be fine.


Much appreciated. I'm already working that way but finding it hard to get anything other than a 20 moa for this model Savage. I'll probably end up contacting one of the company's that make them and see about getting one. Thanks again for the help. - Jmike
 
What XTR said above.

With a Nightforce NXS 12-42 and a 30 MOA rail, mine came up exactly enough for 1,000 with no travel left. I still added a .015" stainless shim under rail. I wanted more for changing conditions. I also would never shoot rifle at less than 500 yards, so I dont need to come down that much.

Ken Farrell makes custom bases. I think the 30 is a stocked item but cab make a 35/40 etc.
 
I think that in general the scope manufacturers send the scopes out "bore sighted" as it were with the erector in the center of the travel range. What that means is that you effectively lose about 1/2 of the scopes travel since that's about where it is going to zero for 100 yards.

I've also read that at the extreme ends of the travel you get limited windage adjustment, and that it could be hard on the springs to live fully compressed all the time. (people worry about it in mags, how much more would you think it would be bad for a precision device like a scope?) Now you put a BR or an NXS on the rifle and they both have about 40 MOA of adjustment, the Competition has 60MOA. A 308 with a reasonable chance of hitting the target at 1000 yards needs between ~29MOA and 36MOA from a 100 yard zero depending on the bullet and load so you can see where the scope with the erector centered won't make it.


With a 20MOA rail you should be about at the bottom of the travel, but sometimes the top of the rifle is cut a little differently. The top of the back of a R700 is flattened to allow a clear view of irons (so I've read) which can lower things a bit more. With a 30MOA rail my 36BR is 6MOA off of the bottom at 100 yards with about a turn left at 1000. My 42NXS is less than one turn from the bottom. (I almost never shoot it at ranges less than 300 so I forget)

When I ordered my Defiance action I ordered a 30MOA rail assuming it would need the same rail that the R700 needed, I was wrong. The top of the action is not flattened so it only needed a 20MOA, and I ended up unable to get a zero inside of 300 yards, which is not a big deal for me. I've never fired the rifle inside of 200 yards, and other than load work at 300 it's rarely ever fired inside of 600 yards. What that means to me is that my erector springs don't get crushed as hard getting out to 1000 and where I shoot most of the time I'm actually closer to the center of the travel.

Just telling the story for a couple of data points to maybe help.
 
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Thanks for the responses. I went to my machinist friend today and we basically made a 40 moa out of the 20 moa rail that I had. I think that will be perfect for my setup as like you, i'm never going under 300 and mostly will be shooting 600 and above. If I do need to go for less, i can always shim the front just a bit. Either way, i should have plenty of elevation now to work with. Thanks again for the help. - Jmike
 
For my shimmed base and 30 MOA rail (and shim) set up for 1,000 yard shooting, to shoot loads at 100, here is what I do. I can bring mine down to a 500 yard zero. With my loads that is around 10-11 MOA up from 100 yard zero.

I use a large white sheet of paper, with a small dot at the bottom (POA) and at 10" above that, I make a mark and another 1" above that. Aiming at the bottom dot will put my rounds somewehere between those two for POI (depending on the load). This way I can test loads at 100 yards w/ a 500 yard zero.
 
Something seems pretty odd here. Nightforce scopes come from the factory optically centered. Depending on which model year you have, your NF Competition scope has either 55 or 60 MOA total elevation travel. This means you should have either 27.5 or 30 MOA up, prior to any adjustment. With a 20 MOA base, that increases to 47.5 or 50 MOA total upward travel. If you subtract out 2.5 MOA for a 100 yd zero (it's probably much closer to 1-5-2.0 MOA in reality), you should have approximately 45 or 47.5 MOA total upward elevation adjustment to reach 1000 yd from a 100 yd zero.

To be very generous, there is no reason you should need more than 40 MOA to reach 1000 yd from a 100 yd zero with a .308, even with a short barrel/very slow load/mediocre BC bullet, etc. So your lack of sufficient elevation adjustment makes no sense to me at all. Is your base really that far off? When you used your muzzle velocity to estimate how much elevation you'd need to get to 1000 yd from 300 yd, exactly what was that estimate in MOA?

Even with a relatively slow commercial 175 gr load out of a 24" barrel .308 bolt gun I used to have, I was able to get to 1000 yd with no trouble. That was using a NF 12-42x56 scope with a 20 MOA base that only has 45 MOA total elevation adjustment (compared to your 55 or 60 MOA). That setup required ~35 MOA to get to 1000 yd from a 100 yd zero, and I estimate I had somewhere very close to 40 MOA upward adjustment remaining from a 100 yd zero.

Bottom line - the numbers aren't adding up for your current situation. Going to a 30 MOA base may solve the issue, but it creates other issues that I would personally try my best to avoid if I were in your shoes. To me, not being able to zero a rifle at anything less than 300 yd is unacceptable for many reasons. Further, unless there's something important you have left out, I can't understand how your setup could be that short on elevation travel. In other words, you really shouldn't have to go to a 30 MOA base and my suggestion would be to figure out the real reason, rather than going to a less than ideal solution. Are you absolutely sure you have a 20 MOA base? If you actually have flat base, the numbers would make a lot more sense. Anyhow, best of luck with it.
 
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My NXS when I 1st bought it w/ a 100 yard zero had 19 down and 24 up.

No, not all Nightforce scopes have that much travel. The 42X NXS has the least travel.

My rounds are 2750 FPS out of a 30" barrel.

I'm shooting a 175 SMK, BC of .496.

I have a 30 MOA base.

Why does zeroing a rifle more than 300 a problem? The bullet does not care where you zero it. As long as you can re-set zero for the distance you compete at, no problem.
 
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I have 4 of the 12-42x56 NXS scopes and two of the 8-32x56. I know the elevation travel of my scopes and I also know the math. I have spoken with the folks at NF in the past and been informed that their scopes are delivered optically centered. That of course does not rule out the possibility that knobs got tweaked somewhere between, possibly at the dealer, but that doesn't matter. If the knob got tweaked, it won't change the overall travel and will simply change the adjustment required to reach a particular zero. My 24" rifle with a 20 MOA base required exactly 18.4 MOA down to zero at 100 yd with the 175 load I mentioned. I had just a fraction over 40 MOA total upward adjustment left, exactly as I stated, and required just under 35 of that to zero at 1000 yd. My math was correct. FWIW - I have also shot 175 SMKs at almost exactly 2750 fps out of a 30" barrel out to 1000 yd using NXS 12-42x56s mounted on 20 MOA bases with no trouble whatsoever. This was at ~420 ft above sea level and did not require a 30 MOA base. Nor was the scope right at its limit of travel.

12-42X56NXStradeRiflescope%7CNightforceOpticsInc_zpsbca0c21a.jpg


Depending on whether the OP has the 2013 or 2014 Competition scope, they are listed at 60 MOA or 55 MOA total elevation travel, respectively. That should leave from 5-7 MOA more upward elevation travel with a 20 MOA base than the 12-42x56 with the same base. Even adding in a couple MOA variance for good measure between two different scopes, the OP should have had in the neighborhood of 45 MOA upward adjustment left from a 100 yd zero. Even a 175 SMK at 2600 fps should require less elevation travel than that to reach 1000 yd. If his MV is low enough to account for that, or the base on the rifle is that far off, I view that as a problem that needs to be corrected by some measure other than shimming or using a 30 MOA base.

Here's one reason I don't favor a rifle that can't be zeroed at less than 300 yd. I do most of my up front load development at 100 yd. Less effect from wind, and it tells me everything I need to know. Although doable, I find it less than precise and a PITA to set up targets specifically to account for an extra 4-5 MOA difference between POA and POI because the scope is bottomed out on elevation travel. There are plenty of other reasons. The OP asked for help with this issue and I'm not trying to be a dick, but simply offering my take on the situation. Without more information, I can't pinpoint exactly what it may be (cant of base way off, scope adjustment problem, load issue, etc.), but it's possible there is some other issue above and beyond a simple lack of elevation adjustment that's worth looking into.
 
I was speaking specifically about my elevation in my response.

I explained above how I also test loads at 100 yards with a 500 yard zero. POI is different but the same result.

My scope was new. Must have been off from the mfg as XTR pointed out above.
 
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Not sure if i can clear up some issues or muddy the waters more but i'll definitely try. On the first scope, it was a 12-42X56 with 45 minutes of adjustment. Yes the rail plainly states NF 20 MOA on top of it (plus i mic'ed it and there was~0.035" of difference from end to end). I put the scope on the base, went to 300 yds with 155 Noslers loaded with 4895 (not sure exact grain, load data is at home) and zeroed in. I can also do the math and with the zero on elevation that i had at 300 and going to shoot 1,000 that weekend it was evident that i wouldn't have enough elevation on the scope to reach. I added 0.015" shim under the back of the rail and went to the 1,000 yard line. I was able to shoot at that distance with that set up but only had ~ 1 MOA of elevation travel remaining.

I purchased the 2013 model Competition (60 MOA), mounted it on the rail and with my previous experience with the gun, the additional elevation travel on the new scope i decided to remove the 0.015" shim and replace it with a 0.010" shim. Thought process was that i would be able to reach the 1,000 with additional travel on elevation with this setup. I did not have a zero prior to shooting as we had unlimited sighters in the first string. Started at the 800 yd line, took 8 shots to zero and it was pretty evident at that time that i would not have enough elevation travel when we moved back to the 1,000 yd line. At 800 i was shooting 155 Noslers with 46.5 grains of Varget and they were to hot for my gun. Had bolt issues and pressure indications on the brass. When i moved back to the 900 yd line, i shot a friends ammo - 185 Berger Juggernauts with Varget powder (not sure exact load but have it at home), came up ~5 minutes on elevation and was good. Went to the 1,000 line and was out of elevation.

The math issue is what originally started this thread as from everything i've read/heard/been told, i should have not had any issues at all at 1,000 with the Competition scope and a 20 MOA rail setup. That's why i asked if there was somewhere else i needed to be looking instead of making the adjustment with the rail.

I really appreciate any and all responses and believe me, i don't take anything as being personnel. As i stated before, i'm very new to this and am really trying to learn all of the aspects that i can. I have a lot of friends who shoot Palma guns but they're not a real big wealth of knowledge when it comes to the scope/rail issues.
 
Something seems pretty odd here. Nightforce scopes come from the factory optically centered. Depending on which model year you have, your NF Competition scope has either 55 or 60 MOA total elevation travel. This means you should have either 27.5 or 30 MOA up, prior to any adjustment. With a 20 MOA base, that increases to 47.5 or 50 MOA total upward travel. If you subtract out 2.5 MOA for a 100 yd zero (it's probably much closer to 1-5-2.0 MOA in reality), you should have approximately 45 or 47.5 MOA total upward elevation adjustment to reach 1000 yd from a 100 yd zero.

To be very generous, there is no reason you should need more than 40 MOA to reach 1000 yd from a 100 yd zero with a .308, even with a short barrel/very slow load/mediocre BC bullet, etc. So your lack of sufficient elevation adjustment makes no sense to me at all. Is your base really that far off? When you used your muzzle velocity to estimate how much elevation you'd need to get to 1000 yd from 300 yd, exactly what was that estimate in MOA?

Even with a relatively slow commercial 175 gr load out of a 24" barrel .308 bolt gun I used to have, I was able to get to 1000 yd with no trouble. That was using a NF 12-42x56 scope with a 20 MOA base that only has 45 MOA total elevation adjustment (compared to your 55 or 60 MOA). That setup required ~35 MOA to get to 1000 yd from a 100 yd zero, and I estimate I had somewhere very close to 40 MOA upward adjustment remaining from a 100 yd zero.

Bottom line - the numbers aren't adding up for your current situation. Going to a 30 MOA base may solve the issue, but it creates other issues that I would personally try my best to avoid if I were in your shoes. To me, not being able to zero a rifle at anything less than 300 yd is unacceptable for many reasons. Further, unless there's something important you have left out, I can't understand how your setup could be that short on elevation travel. In other words, you really shouldn't have to go to a 30 MOA base and my suggestion would be to figure out the real reason, rather than going to a less than ideal solution. Are you absolutely sure you have a 20 MOA base? If you actually have flat base, the numbers would make a lot more sense. Anyhow, best of luck with it.


Whether it adds up on paper or not in some setups it takes a 30. In my case I have two NF scoped that both need a 30 to get to 1000 on my R700. If the knob quits turning before you get the bullet where it needs to be you need more rail.
 
Whether it adds up on paper or not in some setups it takes a 30. In my case I have two NF scoped that both need a 30 to get to 1000 on my R700. If the knob quits turning before you get the bullet where it needs to be you need more rail.

Wade,
Not disputing that in any way as I recall seeing you mention that in other posts. All I was trying to point out is that if you run out of elevation, there a few likely sources, of which the scope travel is one. Fortunately, I haven't been in that situation. But if I was, the first thing I would check would be total elevation travel on the scope. If it was off by enough to prevent me from reaching 1000 yd with a .308, it would be going back to Nightforce for either repair or replacement. If the scope had the stated elevation travel, I'd be looking at the base next. I do a lot of things at 100 yds including both load development and various forms of training. Although it can certainly be effectively used for a number of types of shooting, I'd personally not want to have a rifle setup that cost anywhere from a couple to several thousand dollars that I couldn't zero at 100 yd unless I had exhausted possible way of rectifying whatever the underlying issue was. Maybe that's just me. If it didn't affect the major uses of the gun, I can easily understand that installing a 30 MOA rail is the simplest fix in such a situation.
 
With my 185 juggernaut load i need right at 32 MOA at 1000 here at sea level.....With a 100 yard zero on my rifle and a 20 MOA integral rail (F Class Panda action) i only had about 32 MOA of up travel on my 12 X 42 X 56 NXS (Nightforce ultralight rings)......I bought a set of Burris rings with the inserts (.010) and now i have another 10 MOA of travel, problem solved......Quick easy fix.
 
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In case anyone is still interested, machined 0.035" more taper (was originally 20 moa rail) into the rail which should put it right about the 40 moa mark. Loaded up 155 Nosler bullets with 44.0 grains of 8280 XBR powder, chrono @ 2964 fps and at 300 yds., i'm 12.25 moa off of the bottom stop. This left me with ~42 moa additional travel in the scope (I know, should be more with the scope supposedly having 60 moa total). Everything looks great and i'll go from here. Thanks again to everyone for their time and comments, it is really appreciated and hopefully, i'll get to see you out on the range sometime and shake your hand.
 
Interesting stuff. I haven't been doing this long but I would have never though a 30 base would be needed to reach a 1000 with a 12 x42 nxs.

My receiver is an older rem700 with a 20 base. I have a 12 x42 nxs and I am about 30 minutes on the scope at 1000 with 185s and a 100 yard zero. My zero is about a half minute from bottoming out the elevation knob.
 
In case anyone is still interested, machined 0.035" more taper (was originally 20 moa rail) into the rail which should put it right about the 40 moa mark. Loaded up 155 Nosler bullets with 44.0 grains of 8280 XBR powder, chrono @ 2964 fps and at 300 yds., i'm 12.25 moa off of the bottom stop. This left me with ~42 moa additional travel in the scope (I know, should be more with the scope supposedly having 60 moa total). Everything looks great and i'll go from here. Thanks again to everyone for their time and comments, it is really appreciated and hopefully, i'll get to see you out on the range sometime and shake your hand.

Good to hear it worked out.
 
In case anyone is still interested, machined 0.035" more taper (was originally 20 moa rail) into the rail which should put it right about the 40 moa mark. Loaded up 155 Nosler bullets with 44.0 grains of 8280 XBR powder, chrono @ 2964 fps and at 300 yds., i'm 12.25 moa off of the bottom stop. This left me with ~42 moa additional travel in the scope (I know, should be more with the scope supposedly having 60 moa total). Everything looks great and i'll go from here. Thanks again to everyone for their time and comments, it is really appreciated and hopefully, i'll get to see you out on the range sometime and shake your hand.

Doesn't matter if you only have ~42 up, that will be plenty, more than enough. The key is that you also have plenty left on the low end to zero at 100 yd (or less) if you wish to do so. So your solution worked at both ends of the travel, good to hear. Enjoy shooting with it and thanks for the update!
 
Richard at Near manufacturing will make you just about anything you need and he will also tell you having a scope adjusted at or near it's limits either way is not good on the scopes internals and he has 10 MOA to 70 MOA products and he is really good with numbers when it comes to figuring what ya need as he is a machinist/ competitor and has won a few matches ! Give him a call but I would find an optic with the most elevation and give him a call ! His products are extremely expensive but well worth it as his machining ability is amazing! Richard Near!
Near Manufacturing - Rifle Scope Bases
 
I checked the website and those look like great rails/rings. I'll definitely keep him in mind should i ever need another. I was able to machine the existing NF i had (probably sacrilegious to some) and make it work out. Looking forward to shooting a 600 yd. MR match next weekend and we'll see how it does. I can tell you now that it will do better than i can but i'm having a blast trying. Thanks for the reply.