Problem: Using most of my vert adjustment to zero

[Bawlmore]

Hello all,

I'm running into a problem I've never encountered before, using up A LOT of my vertical adjustment to get my scope to zero. When the scope is zero'ed at 100 yards, I have 8MILS of "up" remaining, but there are 14MILS below the zeroing point that I don't get to use. Here are a list of the parts I'm using:

700 Action
Badger 20MOA Rail
Seekins 30mm Medium Rings
Argos BTR 6-24x50 (3 different ones)

When I first encountered the issue, I thought the Argos scope was bad, and requested a second model through their warranty program, 4 days later I had a new scope too mount... same exact problem and remaining number of mils (8). Athlon was nice enough to send me a third scope, but the issue is still the same. I should note that all 3 scopes tracked well and did well in a box test, so I don't think there is any problem with them now. All three scopes were zeroed and fired at the range, and performed great except for the limited up travel.

I'm starting to think the scopes are not at fault, but rather I have a faulty badger rail or seekins rings, what would be the best way to test them??? I don't own any other 30mm rings, bases, or 30mm scopes, so I'd really like to avoid buying new stuff just to trouble shoot.

Assuming the scope zeroes at mechanical zero, and the 20MOA rail provides 5.56 MIlLs of built in elevation, I should be somewhere near 16.6MILS up and 5.4MILS down... not 8 and 14.

 

[XTR]

It may be the way the top of your R700 action is cut. When I first started shooting F-TR I discovered that the rifle that I was shooting needed a 30MOA rail to get to 1000 yards with my NF scope.

I never bothered to get too involved in the why, just that was what I needed so that's what that action wears.

 

[Bawlmore]

It may be the way the top of your R700 action is cut. When I first started shooting F-TR I discovered that the rifle that I was shooting needed a 30MOA rail to get to 1000 yards with my NF scope.

I never bothered to get too involved in the why, just that was what I needed so that's what that action wears.

This could be true, I guess I'll need to try a friend's scope and rings on the base and see what happens. It looks like swapping parts is going to be the only way to troubleshoot.

 

[eric32]

Burris just came out with the tactical 6 screw version on the Signature Zee Rings. Might help you with additional 20MOA built in the rings and base might give you back some of the scope adjustment

 

[M-61]

Just a thought: Can that rail be mounted backwards on that action?

 

[JohnKielly]

Seen barrels that don't point where they should & others that droop way more than I would have expected.

 

[carlsbad]

Doesn't make sense. Get another pair of eyes on it and you'll figure it out.

 

[Zero333]

I have a Savage 10 action that has a 5 mil backward slope.

 

[Bawlmore]

Burris just came out with the tactical 6 screw version on the Signature Zee Rings. Might help you with additional 20MOA built in the rings and base might give you back some of the scope adjustment

I have considered these, however I think it would just be a bandage and not actually fix the inherent problem.

 

[Bawlmore]

Just a thought: Can that rail be mounted backwards on that action?

Confirmed that it's not on backwards, it's sloping in the proper direction.

 

[Bawlmore]

Seen barrels that don't point where they should & others that droop way more than I would have expected.

I thought this as well, however this is a secondhand rifle, and the original owner had no issues with zeroing, although he had different scope and rings. I'm going to try and put a friend's scope and rings on it this weekend and see what happens.

 

[eric32]

I have considered these, however I think it would just be a bandage and not actually fix the inherent problem.

If you have ruled out a scope issue, rail issue and made sure the scope base is truly stress free.

You might come to this as a conclusion and a fix

 

[XTR]

In the case of my R700 I've used two different NF scopes (8-32BR and a 12-42NXS) and two different sets of rings and two different rails and 3 different barrels on it, and no matter the configuration it needs a 30 MOA rail. (badger steel rings and rail, NF ultra light rings and EGW rail)

I figured out my "problem" on Monday before the first match I ever shot. It occured to me to see if my scope had enough travel to get to 1000. At the time I was shooting 175SMKs out of a 24 inch barrel, nope the 36MOA I needed was not there. I had a 30MOA rail from SWFA in two days.

Now consider the following:

• both scopes have just over 40MOA of travel
• With both scopes, using a 30MOA rail, the scope will get down to a 100 yard zero with less than a turn left on the knob.
• that it takes 30MOA+ to get to 1000 with a 308 so a 20 wasn't even close to enough
• A 100 yard zero on a flat rail would put both well into the top half of the travel
• Both scoped work on other actions with 20MOA rails, thus my conclusion that it is the top of my particular R700 that is different
• This is the second person other than myself that I've seen post a similar comment
• I never really cared about the why, just put on the rail it wants and shoot

 

[Bawlmore]

If you have ruled out a scope issue, rail issue and made sure the scope base is truly stress free.

You might come to this as a conclusion and a fix

Eric,

Agreed, but I'm not convinced the rings or scope aren't at fault just yet. The Burris rings look really nice, I wish I had bought them over the Seekins rings in the first place.

 

[Scott Harris]

As John Kielly stated, some barrel muzzles/bores have a lot of curvature in them. This is especially true for sporter contours. If the muzzle is indexed at the 6 o-clock position, then the bore is pointing down as the bullet exits the muzzle. To compensate, you have to use a lot of your scope elevation just to get it zeroed. This is why many gunsmiths "index" the muzzle in the 12 O'clock position. The simple fix is to get rings that add elevation, like the signature zee rings. If you don't like that answer, you can always take your rifle to a gunsmith and have him re-index your barrel. But that would be quite expensive...might as well get a new barrel.

Now, if the barrel was indexed at the 3 or 9 o'clock position, then you'd be running out of windage to zero it. But the easy fix would still be available: signature zee rings.

 

[Bawlmore]

In the case of my R700 I've used two different NF scopes (8-32BR and a 12-42NXS) and two different sets of rings and two different rails and 3 different barrels on it, and no matter the configuration it needs a 30 MOA rail. (badger steel rings and rail, NF ultra light rings and EGW rail)

I figured out my "problem" on Monday before the first match I ever shot. It occured to me to see if my scope had enough travel to get to 1000. At the time I was shooting 175SMKs out of a 24 inch barrel, nope the 36MOA I needed was not there. I had a 30MOA rail from SWFA in two days.

Now consider the following:

• both scopes have just over 40MOA of travel
• With both scopes, using a 30MOA rail, the scope will get down to a 100 yard zero with less than a turn left on the knob.
• that it takes 30MOA+ to get to 1000 with a 308 so a 20 wasn't even close to enough
• A 100 yard zero on a flat rail would put both well into the top half of the travel
• Both scoped work on other actions with 20MOA rails, thus my conclusion that it is the top of my particular R700 that is different
• This is the second person other than myself that I've seen post a similar comment
• I never really cared about the why, just put on the rail it wants and shoot

I don't think a 30MOA rail is going to solve the issue here, because that only adds 10MOA (2.8MIL). This would bring me too 10.8MIL up and 11.2 down, it seems absurd to me that even with a 30MOA rail I wouldn't be zeroing near the mechanical zero. The 10.8MIL is equal to 39MOA, which isn't going to be enough to suit my needs; I'm aiming for about 65MOA / 19MIL

 

[Bawlmore]

As John Kielly stated, some barrel muzzles/bores have a lot of curvature in them. This is especially true for sporter contours. If the muzzle is indexed at the 6 o-clock position, then the bore is pointing down as the bullet exits the muzzle. To compensate, you have to use a lot of your scope elevation just to get it zeroed. This is why many gunsmiths "index" the muzzle in the 12 O'clock position. The simple fix is to get rings that add elevation, like the signature zee rings. If you don't like that answer, you can always take your rifle to a gunsmith and have him re-index your barrel. But that would be quite expensive...might as well get a new barrel.

Now, if the barrel was indexed at the 3 or 9 o'clock position, then you'd be running out of windage to zero it. But the easy fix would still be available: signature zee rings.

Original owner of the rifle did not have a zeroing issue that I'm encountering. The scope base and barrel have not been swapped or modified.

 

[Scott Harris]

Original owner of the rifle did not have a zeroing issue that I'm encountering. The scope base and barrel have not been swapped or modified.

some scopes have much more travel than others. your scope is supposed to have 60 MOA....a lot. So, I dunno, but you still have the easy fix available.

 

[Bawlmore]

some scopes have much more travel than others. your scope is supposed to have 60 MOA....a lot. So, I dunno, but you still have the easy fix available.

The scope I have is advertised for 18MIL (65MOA) but actually has 22MIL (80MOA), counting the clicks. His scope was a bushnell with the same amount of travel. My buddy is going to lend me a NF and some XTR rings to see if they encounter the same issue. It looks like I'll probably end up selling the Seekins rings and buying the XTRs, unless his rings work with my scope... then I'll know I have faulty rings.

 

[fredhorace77]

I have a Savage 10 action that has a 5 mil backward slope.

Same here, sucks because I always have to shim scope bases.