I recently brought a new scope for a rifle I had built. When getting ready to mount the scope I checked the receiver with a straight edge. It is not level. I am wondering what is the best way to approach installing the scope, rings and bases? I would like to stick to Talleys or Leupold Dual Dovetails or Backcountry rings. But, I have not ruled out the DNZ Game Reaper one piece.
This is a rifle for hunting and plinking. Mild caliber—6.5x257R. Do I install the bases to the receiver incline and the lap and bed the rings? Or, do I level out the base and bed with epoxy by tightening the rear screw, letting the front of the base free float? The lap the rings or bed?
How would you approach this issue. Any advice is appreciated. Thanks.
Rick Grimes for Governor "This isn't a democracy anymore"
If I am understanding the question, I mounted a set of Talleys and the ran the straight edge flat with the bottom of the rear base and it was not touching the front mount. There was still a small gap. I didn’t measure it with a feeler gauge, but there is definitely a height difference.
The base would have to be cut at angle rather than flat to make up the difference. In the large picture the straight edge contacts the receiver in the rear for both mounts, but has a gap where the front screw is located.
I have a set of dual dovetail bases. I will check the front/rear thickness with my micrometer to see if they are the same or different. It could be the aluminum Talleys that are to conform the to receiver when torqued down.
Last edited by SWGAShooter; 03/24/24.
Rick Grimes for Governor "This isn't a democracy anymore"
Front dual dovetail mount was same thickness front to back. Since the angle of the receiver is almost the same back to front, probably lapping is the best choice. Unless someone else has a better idea.
Last edited by SWGAShooter; 03/24/24.
Rick Grimes for Governor "This isn't a democracy anymore"
There are two ways you can do the job that work well. One requires more tooling than the other. If you want two piece bases, you will need a straight rod (think ring lap) that can be used to establish the rear base height when all parts are assembled. You can then bed the rear base to correct the height difference. The better/easier alternative is to use a one piece base and bed the rear of it to the receiver when the front of the base is tight to the front ring of the receiver. Do not bed the front of either base to the front ring of the receiver to correct any angular issues. The front ring determines where the barrel is pointed, so if you bed to correct the angle at the front ring that you illustrated in your photos your rifle will shoot low to the point that it may be outside the adjustment range of the scope. Whether you choose a one piece base or two piece, the rear needs to be bedded or the height difference will put the scope tube under a huge stress if not bedded to be straight and stress free.
BangPop: do you think a 30mm aluminum or carbon fiber bar would be light enough to support the rings and base for using two piece mounts? I have the lapping bar but am worried about weight and inducing stress to the mount when tightened down and not supported by the front.
The DNZ mount would work the same as a pic rail I would assume. Probably a lot less work than trying the two piece route. Pic rail is plan B I guess.
Rick Grimes for Governor "This isn't a democracy anymore"
Interesting, I need help with a gun....no make or model, might as well be, I need help with the air. Obviously the front and rear action rings are not level under that streight edge, so they are not the same height, if square. A scope base or bases should be level and centered to the axis of the bore as mounted. First thing you need are bases or a base for that make and model action. Forget shims or Fouxinh up a scope mount job wih epoxy.
“To expect defeat is nine-tenths of defeat itself. It becomes a self-fulfilling prophecy. It is best to plan for all eventualities then believe in success, and only cross the failure bridge if you come to it." Francis Marion - The Swamp Fox
Interesting, I need help with a gun....no make or model, might as well be, I need help with the air. Obviously the front and rear action rings are not level under that streight edge, so they are not the same height, if square. A scope base or bases should be level and centered to the axis of the bore as mounted. First thing you need are bases or a base for that make and model action. Forget shims or Fouxinh up a scope mount job wih epoxy.
And if the base, or bases that are for that action don't fit correctly, then what.........?
Why not use brass shims instead of epoxy. (soda pop can material for shimming works also) You should be able to lay your straight edge along the front of the receiver and use feeler gauge to determine how much shimming you need. A lot more forgiving when setting it up than epoxy.
If God wanted you to walk and carry things on your back, He would not have invented stirrups and pack saddles
Is shim stock used to get a close fit when bedding a rifle, or is epoxy used to get an exact molded fit of the two surfaces that need to mate? Shim stock will get close, but bedding with epoxy will be a mirror image.
I have shimmed three different scope mounts in the past, 7 mm Weatherby mag, 30-06 and.308. All worked fine. You can get within .002-.003 measuring with feeler gauge. Of course you need a good set of calipers or micrometer and a range of shim stock. How much does epoxy shrink and how impervious is it to cleaning products? Not saying it is the only way, just another way that works. Plus you can add more, remove some, or whatever. Pretty hard to do with epoxy. Since the OP has the lapping jig, it should be easier yet.
Back when rifle scopes did not have self centering cross hairs, it was a conventional way to get you scope within the adjustable range of it.
Another thought is what about the recent thread about bedding compounds/epoxies deteriorating in time?
Last edited by saddlesore; 03/25/24.
If God wanted you to walk and carry things on your back, He would not have invented stirrups and pack saddles
Interesting, I need help with a gun....no make or model, might as well be, I need help with the air. Obviously the front and rear action rings are not level under that streight edge, so they are not the same height, if square. A scope base or bases should be level and centered to the axis of the bore as mounted. First thing you need are bases or a base for that make and model action. Forget shims or Fouxinh up a scope mount job wih epoxy.
And if the base, or bases that are for that action don't fit correctly, then what.........?
Then you modify the bases: Get them as close as humanly possible, then glass bed them to the receiver. Rough up the bottom of the bases, and use release agent on the receiver. That way the epoxy is on the bases, and the bases are fit for that rifle/receiver. After that, you shouldn't even need to lap the rings. Pretty simple, and no I would not use soda pop cans or any other kind of shim.
Originally Posted by raybass
I try to stick with the basics, they do so well. Nothing fancy mind you, just plain jane will get it done with style.
Originally Posted by Pharmseller
You want to see an animal drop right now? Shoot him in the ear hole.
Then you modify the bases: Get them as close as humanly possible, then glass bed them to the receiver. Rough up the bottom of the bases, and use release agent on the receiver. That way the epoxy is on the bases, and the bases are fit for that rifle/receiver. After that, you shouldn't even need to lap the rings. Pretty simple, and no I would not use soda pop cans or any other kind of shim.
Have you ever tried shims? I bet not. You could use soda pop material, IF and that is big if, you could find the right thickness which is why I advised brass shim stock in different thicknesses. And no I would not use epoxy. That is about like using a dremel tool for fine metal or stock work.
Maybe the OP has no way to modify the bases.
Another thought is what about the recent thread about bedding compounds/epoxies deteriorating in time?
On the Weatherby 7 mag I did, Weatherby advised using a Remington 700 base along with a shim as the front of the receiver was higher than the back and there was no correct fitting bases on the market.
Burris markets off set scope rings for the same problem for misaligned scope bases.
First, put your straight edge flat on the front of the receiver letting the straight edge go over the rear of the receiver. I suspect that you will find that the front and the rear of the receiver are parallel. Not the same height but parallel. Measure the difference between the bottom of the straight edge and the top of the rear of the receiver. That will be the difference in base height. The receiver sure looks like a Remington or clone and as pointed out the bases are different height.
Interesting, I need help with a gun....no make or model, might as well be, I need help with the air. Obviously the front and rear action rings are not level under that streight edge, so they are not the same height, if square. A scope base or bases should be level and centered to the axis of the bore as mounted. First thing you need are bases or a base for that make and model action. Forget shims or Fouxinh up a scope mount job wih epoxy.
