My scope mounting routine.

[Altitude sickness]

I mounted a scope on my newly acquired Dakota 76 in .338 WM today. I’ll go thru my steps and maybe someone can give me an easier, better way to achieve a quality mount. Or perhaps someone can use some tips.

Without going to a Pic rail there are limited options for the Dakota 76 . Talley and Leupold. I bought Talley bases and rings.

My first step is to completely remove the oil from the bases, rings threads and bolts. Most manufacturers Torque specs are for dry components not oiled.

They are shipped with a protective film of oil. So I use brake cleaner to remove the oil from all surfaces. It also removes any remaining minuscule shavings left over.

 

[Altitude sickness]

Unfortunately for most African style hunting rifles one piece mounts and Picatinny rails are verboten. So we use 2 piece mounts. Which are prone to alignment defects.

from Murphy rail manufacturing. https://www.murphyprecision.com/scope-bases/dakota-arms/
“Most modern rifle actions are machined to fairly close tolerances, but before the common use of CNC machining equipment, tolerances were much looser. In addition to any errors in the original machining, most rifle actions are polished afterward to remove any tooling marks. While this leaves a pleasing finish, most freehand grinding and buffing can lead to errors of several thousandths of an inch in critical areas. Without bedding, the only solution is to tighten the scope base screws enough to warp the scope base and rifle action sufficiently to make close contact. This warpage can lead to a host of accuracy robbing problems in both your rifle action, and scope.”

So after a thorough cleaning I install the bases and rings then check them with my slide alignment tool.

https://www.amazon.com/Scope-Ring-Alignment-1/dp/B0BV161PF3/ref=mp_s_a_1_8?crid=YU7ROCMYAEXS&dib=eyJ2IjoiMSJ9.Y6wBAnKUmCuKcghHdq62SpMWXMKs5iieOZAsaTeuW7OgrhxIM0ecrUYypb-kI6LOZG7A5aJM7PjuzX87d_nQNwsPk_Sojx8WsbLIdQ_RNVJXpFdYvAiV6fMnikuSLV_0Gm6lWTMtF7Nv3sDCXqcLCBgGy_8lW4ivmPONwVV7x5k4EgkoPY7nvNtxuAqqN5Jj2YYcjwFOfpXQ7vuz0FZsOA.Xr2dMVfHCzZRjQSh8BfqO0atXc2hnydVyfa2P8tUMwk&dib_tag=se&keywords=rifle%2Bscope%2Balignment%2Btool&qid=1785887883&sprefix=rifle%2Bscope%2Bal%2Caps%2C214&sr=8-8&th=1&psc=1

 

[Altitude sickness]

Most hunters do not go to the extremes as the extreme long range guys do. Benchrest and the 1000 yard to 2 mile guys must perform these mundane tasks.

Also the owners of expensive optics that want their scopes operational and defect free.

Unfortunately my slide alignment tool showed a slight bind from the Talley rings. If I was using a more robust scope tube like
Nightforce Atacr, S&B or Tangent Theta I would have called it good. But I was mounting a 1” tube Swarovski so needed more precise alignment to eliminate 100% of any bind or high spot contact points.

 

[Altitude sickness]

So out come the dreaded lapping rings. I should move my earlier oil stripping step to after the alignment step. Because now I’m about to get a greasy gritty mess all over the items I just cleaned.

(Rings bolts partially removed) I was loosening and removing the bar then remembered to snap a pic before removing the bar.

 

[Altitude sickness]

After lapping, everything had to go through an even more rigorous cleaning to ensure no grease or grit remains. Then try the slide alignment again. This time with a lite flick of the finger the sliding ring easily glides back and forth showing 100% alignment with zero bind. And the lapping also removes the high spots . Which left in would have been the only contact points between the rings and scope.

This puts uneven pressure on a tube and drastically reduces the holding power of the rings

If you look, you can see where the lapping compound removed the high spots giving perfect alignment and perfect contact.

 

[Altitude sickness]

Next, I bring out the scope level kit and bore sighting tool. And now I have one happy scope sitting on a beautiful Dakota rifle. Waiting eagerly to be shot.

 

[Altitude sickness]

It would be much easier to slap a high quality one piece base and rings on or a Pic rail.

Also to get 100% perfect bases and rings the price of those brands are double and triple the cost of Talley. And are not available in all rifle brands.

 

[Tex .416]

It would be much easier to slap a high quality one piece base and rings on or a Pic rail.

Also to get 100% perfect bases and rings the price of those brands are double and triple the cost of Talley. And are not available in all rifle brands.

This all day long!!!!

Using vertically split rings is the root of the trouble. Lapping does not fix the problem. It is a poor design. Why they continue to exist is hard to understand. They are only one step less bad than windage adjustable bases, which are absolute garbage.

There was a good study done 15 - 20 years ago, which I cannot find right now, which compared different styles of rings for uniformity/deformity. Vertically split rings can be manufactured to essentially perfect tolerances. However, mounting them is the beginning of the problem as they cannot be tightened evenly like rings with horizontal seams and caps that are tightened down separately from the cross bolt pressure. Vertically split rings are very challenging to mount with even pressure due to the design and result in uneven pressure on the scope tube. That leads to the erector binding and ultimately increases the likelihood of failure. Lapping does not fix the problem. Every time they are loosened and retightened, they may or may not come back to the same alignment. Hitting the side of a buffalo or elephant probably will not matter, but if they are loosened, the scope is bumped while the vertical rings are loosened risks things changing. I know 20 guys will chime in they use them all they time and never had a problem. Great, awesome, happy for you. They still are a poor design that is easily bested.

If you do not want to use a full length Pic rail, buy a full length Pic rail from Murphy Precision who makes them for the Dakota 76, cut pieces to fit the front and rear of the receiver and cut out the middle section. Then mount with Pic rings. I've cut out the middle of a Pic rail with a hacksaw, filed the cut face smooth, hit with black spray paint and bingo, instant bases with the middle open. No big deal.

Scope Mounts for Dakota Arms Rifles

Scope Bases for Dakota Arms Rifles

www.murphyprecision.com