Uh-oh on some scope mounts. and maybe SCOPE too.


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Topgun
November 27, 2004, 09:48 PM
I'm picking up a Savage Varminter tomorrow and when I picked it out, I was elated that my OLD Bausch & Lomb mounts matched the holes in the receiver making me think that I could use my BalVar 8 on this gun.

However the mounts are for a Win 70 and they are a different radius from the Savage receiver. The FRONT one may make it as it is a smaller radius so I think the weight will bear on the edges of the mount. But the rear one is for the flatter Winchester rear receiver and that would leave the mount depending on the screws alone and a very small contact with the receiver.

Uh oh.

Think shimming would work? I really would like to have the B&L mounts machined to match the Savage receiver but don't think any of the local gunsmiths could handle all the "keeping level" that it would take.

Suggestions?

If I need to get a NEW scope, any suggestions there? Don't need the Swarovski Swiss Bank Acct model. Just a good solid variable that holds its reticle between powers.

?????????????

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rust collector
November 27, 2004, 10:03 PM
shouldn't be a tall order for a smith.

A. install front mount and scope, line up rear mount with hole in receiver.

B. bore sight the scope with windage and elevation adjustments centered, using shim stock under rear mount.

C. measure shims and machine rear adapter accordingly.

This mounting system was far better than current designs at adapting to a variety of rifle configurations. I wish this mounting system was still common so I could buy one wonderful scope and use it on whatever rifle I felt like shooting, rather than a raft of mediocre glass.

Jonathan
November 28, 2004, 07:40 PM
The BalVar 8 would be a collector's item, correct? Maybe it would be best to not cut it up?


You could do a serious expoxy bedding job between the mounts and the receiver, but this would be an extreme that I've never heard of before. Advantages would be no (permanent) modifications, the best possible match between the parts, and potentially a do-it-yourself job. On the other hand, this is a very extreme bedding job, and I'm not sure if it would have the structural integrity desired.


Personally, I would consult with a gunsmith experienced with precision rifles/optics. I've seen too many botched jobs from gunsmiths who cater to the casual hunting crowd (shimming with layers of TAPE, for example).

musher
November 28, 2004, 08:25 PM
EPOXY!

Use the brownells release compound to get it off your parts after molding the shims. You can also use paste wax or something like that, but the brownells stuff works well and is easy to apply.

Go to system 3 and buy a little of their phase 2 epoxy, silica powder, and aluminum powder. You can also order epoxy dye to color the parts black or white or whatever.

Coat all the pieces in release compound, let it dry, and coat them again. Be sure to get it in all the holes and on the screws. Coat a lot more of things than you think you'll get epoxy on--trust me!

Mix up the epoxy. Reserve just a little back, then mix a 50/50 al and silica powder in the rest. They both make things stronger. Add powder a little at a time until you get the right consistency. Mix enough powder with the epoxy so it will stand up on it's own, but isn't dry. Sorta like stiff peanut butter with a wet surface.

Use a model brush to 'prime' the mating surfaces. Underside of the mount and the receiver. Don't drip any into the holes. This helps make a nice 'polished' mating surface.

Put the screws into the mount and glob on the 'peanut butter' mix until you've got enough to fill the gap when things are assembled. Keep it off the screw threads.

Now mount the assembly on the reciever (coated with release compound, remember?) You should have expoxy squeezeout all around the mount.

After things get to the green stage (epoxy is not tacky, but still sorta soft to a knife), Use an exacto or other fine blade to scribe a line along the edge of the mount where the expoxy squeezed out. You'll use this as a guide to trim the part after it's cured.

Now disassemble remove the screws and knock off the epoxy shims.

Using a fine saw trim the parts a bit proud of the trim line you scribed. If you used enough epoxy, you shouldn't even need that trim line, as it should be apparent where the base of the mount ended. You'll probably want to trim them before curing, as the epoxy gets a lot harder after final cure.

OK, now the phase 2 epoxy is a hi-temp compound that requires curing at elevated temps to reach full strength. Read the directions that came with the epoxy and cure your parts in the oven at the recommended temps.

The advantage of using the 2 phase stuff, is that it will be MUCH more resistant to deformation than everyday epoxy when things get hot, as rifle receivers may. Disadvantage, is that the old standby of heating up a part to get epoxy to let go of it doesn't work as well. If you're not concerned about hi-temp stability, then you can use the regular brownells steel bedding compound or any other kind of (non-5-minute) epoxy for this.

After secondary curing, let things cool. Use a random orbit sander and 220 to knock the parts down flush to the base of the rings. You can use the 'tape' strategy to make'em dead flush like you would a butt pad. Bolt them to the mount using some bolts the same size as your mounting screws while sanding the parts flush.

Advantages are you can do this yourself. With a little care you've got a professional looking shim. If you're careful there's no damage to either your rifle or the mounts. It's cheap. It's strong.

At any rate, that's probably what I'd do faced with the same problem.

Then again, I could use it as an excuse to go buy a scope...

Gordon
November 28, 2004, 11:48 PM
Wow you should be a technical writer! I KNOW your technique works and would NEVER fail on a Varmint gun for sure! :)

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