Base Mounting Questions.

[Nub Hippie]

I am installing a DNZ scope mount on a Savage Axis. With the front mount screws tightened down I can slide a sheet of common notebook paper under the mount but with friction, same goes for the front when the back screws are tightened however the tension is much tighter, almost ripping the paper. I cannot see any light under either contact point and can't hear any click from the mount hitting the receiver when tapping on the top of the mount. Should I bother bedding the mount or not? When you torque your screws, what in/lb do you torque to? 25 in/lb seems to be most common. And finally, should I bother with blue Loctite for the screws? if so will 25 in/lb be too much torque due to the lubricating effect of the loctite?

[Stumpkiller]

First check to make sure your base screws aren't bottoming out.

I'd either bed it in J-B Paste, or (better) lay emery cloth on the receiver grit up and slide the base over it with a little pressure to lap the base for a gapless fit. If the base is steel reblue the underside before reattaching.

I use blue Locktite on base screws, and whether or not the mfg. recommends on the ring screws. A 6-40 screw is good at 22 to 23 in lbs.

[Nub Hippie]

Huh, lapping the bottom of the base never occured to me, thanks for the suggestion. They are made from 6061-T6 aluminum and anodized matte black btw.

If I do bed it should I do just the back or both ends? I've most commonly seen it done on the back only while tightening down the front screws tight to align things. All I have to plug the receiver holes is modeling clay and I don't really want to go buy a $7 can of paste wax for one job, any recommendations on how to remove the clay "plugs" once done? seems like it may be a problem in such a small threaded hole.

[PaddyD]

Lapping is better than not, but epoxy bedding is the best way to do it and it is supper easy. Take and rough up the underside of the base and then de grease.. Use the release agent of your choice on the rifle receiver, screw holes and the entire screw. Mix up some epoxy ( for bedding bases, simple JB weld works great and is cheap). Paint the underside of the base with a thin coat of epoxy staying well clear of the screw holes and then screw it down tight. Gaps will be filled and excess squeezed out. Clean well with acetone or other solvent and after about 1 hr just crack the screws loose and back to just barely tight to make sure they don't seize. Next day tighten screws to proper torque and mount the scope.. Lapping the base will not get that perfect contact patch epoxy will give since it is impossible to make the base and the receiver mirror each other unless you use lapping compound between the two parts , but that will totally mess up the surrounding finish.

[sharpshooter]

So what I am understanding is when the front screws are tight, there is a slight gap between the rear mount and the receiver about the thickness of a piece of typing paper? If that's the case, it isn't anything to be concerned about. You don't need any loctite or bedding, just screw it down hand tight. Then lap the rings till they are uniform.

[Nub Hippie]

Actually upon closer inspection it's about 3 sheets in the back and 1 sheet in front when the back screws are tightened instead and there is a noticeable click when tapping on the rear when the front screws are tight so I'm going to bed it this weekend just for peace of mind.

[sharpshooter]

That's nothing more than a little warp in the mount, and it's common with DNZ mount because of all the material removal between the rings. When you screw it to the receiver it will draw it down and it goes back straight again.

[Nub Hippie]

So if I understand correctly, If the mount is warped and I bed it as it sets, I could actually be hurting things more than helping by bedding it so the warp remains? I've checked it with a precision straight edge ruler from the shop but unlike a rail it's kind of hard to find a good area to check on, however when laid in the rings it seems to make flush contact, any way to confirm if it's warped without lapping tools? Suppose I could just check the action with the straight edge to see if it's straight or not instead. Would that be reliable? I went with DNZ to avoid having to lapp my rings. I know some people do all their rings regardless of quality or price but a lapping kit is just something I cannot justify spending the money on at the moment.


Just tried flipping the base around 180 degrees and testing for clearance since I won't be back over at the shop again until tomorrow and I'm impatient. With the front screws tight I can barely get 1 sheet of paper under it telling me the warp is in the mount and not in the receiver unless I'm missing something. Thanks for pointing this out Sharpshooter, a big help as always, saved me from potentially making a big mistake. :)

[Nathan gravitt]

So if I understand correctly, If the mount is warped and I bed it as it sets, I could actually be hurting things more than helping by bedding it so the warp remains? I've checked it with a precision straight edge ruler from the shop but unlike a rail it's kind of hard to find a good area to check on, however when laid in the rings it seems to make flush contact, any way to confirm if it's warped without lapping tools? Suppose I could just check the action with the straight edge to see if it's straight or not instead. Would that be reliable? I went with DNZ to avoid having to lapp my rings. I know some people do all their rings regardless of quality or price but a lapping kit is just something I cannot justify spending the money on at the moment.



Just tried flipping the base around 180 degrees and testing for clearance since I won't be back over at the shop again until tomorrow and I'm impatient. With the front screws tight I can barely get 1 sheet of paper under it telling me the warp is in the mount and not in the receiver unless I'm missing something. Thanks for pointing this out Sharpshooter, a big help as always, saved me from potentially making a big mistake. :)


Did you ever figure out the DNZ? If not, you could put a straight edge on the bottom of the base and see if it will rock. If it does, I would send or take it back.

[Nub Hippie]

Yes i did figure it out and the base and rings were true once torqued down to the receiver. It was as Sharpshooter had stated, there was just some slight warp in the base from the removal of center material, however I believe the rings are machined before that step meaning the rings should remain true once tightened to a receiver that is also true.