Rifle Scopes Am I doing something wrong?

[maximvickers]

New member here. Gave a brief description of past shooting in the new members sections.

I currently have three, what I consider long range rifles and trying to make it four.

I currently have a Barrett 50 BMG with Leupold scope, a Savage 110 ba .338 lapua with a nightforce benchrest scope and a Savage 10 ba .308 with a viper vortex pst scope. I have had no trouble reaching out to and beyond 1000 yards with any of these setups.

Now for my problem. I decided I wanted to give the 6.5X284 a try. Purchased another Savage, this time the long range hunter. Put Warne 20 MOA base on the rifle and bolted on another Nightforce benchrest scope I had picked up for a song. Loaded up some ammo and off to the range to sight in. Bore sighted at the range and realized that my scope adjustment bottomed out before I was on target at 100 yard. I set up a small target where the scope seemed to be pointing. Placed a larger target above this target. Took three shoots to bring my windage in perfect. Fired 4 more shoots you could cover with a quarter. So the gun shoots great just 6 inches high from point of aim.

So my question is, have I done something wrong or is this just the way this set up worked out? None of my other set ups has given me this problem. I have zeroed them all at 100 yards then worked up my chart out to 1200 yards.

Any constructive comments are welcomed. Thanks.

 

[Redmanss]

Which NF Benchrest model? The 12-42x model only has 40moa total travel available anyhow, so that could easily be your issue. If you have the 8-32x (50moa total) then I would be a bit more curious as to why you were running out of elevation, but could still understand if there were slight misalignment in the receiver and/or base as well. Tolerance stacking can add up quick when you're talking about hundredths of an inch to throw you right out the window.

I'd say treat it as a long range setup and zero it at 300yds, keep the elevation available for cold days.

 

[maggitas]

So you say you are bottoming out on the bottom end then is this correct? If so you can cut some shims out of thin aluminum (Tin Can comes to mind) and place it under the rear scope ring between the inside ring and the scope. This should give you some added cant.

 

[maximvickers]

Nightforce 8x32 with 50 MOA. Yes I bottom out the scope on the bottom end. Have 49.5 MOA going up from there. So plenty of elevation for long range shoots. Have not been doing this long enough to not think I had done something wrong. Considering how easy it was with my early 3,set ups.

 

[silentheart]

You said you used a 20moa base? Is it possible the rifle has 20moa build in already? Just a wild guess.

 

[agbm]

If you have 50 moa/2=25moa and add 20moa base= 45moa total up and 5moa down. You should be able to zero at a 100 yards with no problem. Did you reset everything or are you working off the previous owners setup/zero?

 

[SomeOtherGuy]

Did you bed the scope base? I have yet to find a Savage, Remington or Howa where a scope base attached perfectly at both ends without bedding (including picatinny rail bases made by Ken Farrell, TPS, EGW, and Warne). I'm guessing that your base to receiver fit may be far enough off to turn your 20 MOA base into a total of 25 or 30 MOA elevation, which could cause the problem you're having.

 

[SMM123]

I had a similar issue last month with a new set-up. What had happened was that the cross bolt that locks on to the weaver rail on the scope mount was not actually in the slot of the weaver rail. It was sitting on top of the rail, which meant that I bottomed out the adjustments before being zeroed. I could not see it externally because of the design of the mount. It was only after I took the scope off and tried to put it back on that I found the issue.

On another optic that I also purchased for a song, the internals were bad. But it was not a NF.

 

[29aholic]

Shimming the back of the base is going to make it shoot higher. You are tilting the reticle down which is going bring the point of impact up.

 

[maximvickers]

The base was placed directly on the receiver. I did not reset anything. Working straight from the sellers settings. Do not think scope was ever shot however. Scope mounted on a rifle he was trying to sell as a package deal. Condition of scope appears NIB. Where would you suggest I start with settings? I did not bed the scope base. Is there a way I can tell if it needs bedding? I used a feeler gauge .0015 checking edges of base for gaps and could find none. I will check the ring mountings.

 

[SomeOtherGuy]

I did not bed the scope base. Is there a way I can tell if it needs bedding? I used a feeler gauge .0015 checking edges of base for gaps and could find none. I will check the ring mountings.

Most scope bases are flexible relative to the force the base mount screws can exert. Checking whether you need bedding is super simple though. Remove the scope, remove all the screws and remove the base. Check the top surface of the base for flatness against a reasonable straight edge, like a quality metal ruler. It should be flat (straight at the top surface). This is just a check, I haven't seen one yet that wasn't straight/flat. You can even eyeball that.

Assuming the base is straight along its top length, put it back on the rifle and install screws at only one end, front or rear, tighten to normal torque. Check for a gap at the other end, between the bottom of the base and the rifle's receiver. If there is minimal or no gap at the other end (the one without screws installed), then remove the screws and repeat the test with two screws installed at the opposite end. Most base/receiver combinations will show a gap at one end or the other.

To bed the scope base - look up comprehensive instructions already posted here. The short, short version:
-clean base bottom
-apply release agent (shoe polish works) to the receiver all over, and the screws also
-apply epoxy (JB Weld works fine) to the end that had the larger gap
-tighten screws at the other end, ONLY (no screws at the end getting the epoxy - make sure the holes in the base and receiver are blocked off - playdough works fine for this)
-allow epoxy to set

I am not certain this is your problem, but I think it's worth a close look. Bedding the base takes only 20 minutes or so and a very modest amount of materials, and then you have a perfectly mounted base for the rest of the time you use that rifle.

 

[29aholic]

Most scope bases are flexible relative to the force the base mount screws can exert. Checking whether you need bedding is super simple though. Remove the scope, remove all the screws and remove the base. Check the top surface of the base for flatness against a reasonable straight edge, like a quality metal ruler. It should be flat (straight at the top surface). This is just a check, I haven't seen one yet that wasn't straight/flat. You can even eyeball that.

Assuming the base is straight along its top length, put it back on the rifle and install screws at only one end, front or rear, tighten to normal torque. Check for a gap at the other end, between the bottom of the base and the rifle's receiver. If there is minimal or no gap at the other end (the one without screws installed), then remove the screws and repeat the test with two screws installed at the opposite end. Most base/receiver combinations will show a gap at one end or the other.

To bed the scope base - look up comprehensive instructions already posted here. The short, short version:
-clean base bottom
-apply release agent (shoe polish works) to the receiver all over, and the screws also
-apply epoxy (JB Weld works fine) to the end that had the larger gap
-tighten screws at the other end, ONLY (no screws at the end getting the epoxy - make sure the holes in the base and receiver are blocked off - playdough works fine for this)
-allow epoxy to set

I am not certain this is your problem, but I think it's worth a close look. Bedding the base takes only 20 minutes or so and a very modest amount of materials, and then you have a perfectly mounted base for the rest of the time you use that rifle.

Based on this if this is the issue I am betting the front needs bedded as any gap would cause even more tilt than the MOA built into the base. thus adding MOA.
As far as resetting goes you can do it the old fashioned way and run the turret all the way to one end, count the revolutions/clicks to other end and divide in half.

 

[CSTactical]

Nightforce ATACR 5-25x or 5.5-22x , Kahles 6-24x, IOR, Leupold Mark 4 M5 8.5-25x and more, and the Bushnell 4.5-30x . Top of my list would be the Nightforce and the Kahles, the Bushnell for the price.


If we can be of help let me know for we stock most of them.

Mike CSTACTICAL

 

[lawman29]

get a 10 moa base: Ken Farrell, Inc. -- 10 MOA Savage 110 BA and 111 1pc scope mount

 

[maximvickers]

Want to thanks each and everyone for the responses to my question. I took the use a shim in route. I placed a 0.011 shim inside the bottom of the front scope ring. I then torqued screws to the proper setting. Four shots got me on target after bore sighting at range. I then fired two three shot groups. The first group was little low but ended up being .58 inches center to center. Second group was a little better being .3 inches center to center. Figure this is not to bad since these were only the 15th trough 20th shots in the rifle.

 

[maximvickers]

Figured I might as well put up a picture of this rig we have been discussing.

 

[29aholic]

Glad you got it figured out, but I would prefer to shim the front of the mount (or bed it) versus putting the stress on the scope tube shimming the ring.

 

[SomeOtherGuy]

Same thoughts - I would worry that a shim inside the ring will move over time, or with a drop or whatever, changing your zero. Also best not to put stress on the scope tube.