Guys,

I'd sure appreciate seeing some pics of fixtures designed to hold an M70 receiver in a mill vise.

Need to make one to make some custom scope mounts for pre-64 and recent Classic receivers.

Thanks!

Mike

For us nonmachinists I have a question.

When you make the front base, do you use a mill for the whole job or do you use a lathe and then a mill.

I was wondering because I kind of thought that if a peron had a piece of round bar stock one could chuck it in the lathe and then use a boring bar to get the exact size hole as the circumference of the front ring and then mill away what you don't need.

Anybody do it that way? Or do you use a special milling cutter.

How do you do the rear one? Is it just a larger circumference. Or do you use a special milling cutter?

22WRF,

I do it all on a mill. The bottom arc of the front base is done on one face of a piece of 1" square 1018 ... with a boring bar set to the correct diameter.

On an M70 rear base I do the same thing but the diameter is different.

Assuming the charger guide has been ground away on the rear base of a Mauser it is done in two steps. The correct bottom radius is cut away until it just reaches the edges of the block. The the block is set up in an angle vise set to 34 degrees and the edges of the block cut away so that the the flat is about 0.200" wide on each side. The part is then hand fitted to the rear of the receiver so that it bottoms on the deepest part of the arc previously cut.

There are pictures of the some of the process on this thread:

http://forums.accuratereloadin...=699108678#699108678

The individual pieces are then cut for approximate height, drilled for the mounting screws, and the counter bores done. I then mount the blocks on the receiver and the receiver is put on a milling fixture and vised up on the mill bed.

The sides are cut and the tops of the mounts finished to have the correct spacing.

I tend to be "scope poor." That is, I don't have enough for each rifle and spares for each rifle. Am lucky to have enough for each rifle. As a result, I want all of my rifles to have exactly the same spacing between the rings so that my scopes can be moved from one rifle to another without moving the rings. Means I can take spare scopes on a major trip by readjusting the scope's impact point.

Am not at all sure this makes any sense economically ... and wouldn't if you had to pay a smith a decent living to do the work. But for an old retired guy with more time than money and the tools to do the job ... it makes for something to do and provides a nice result.

I do mine pretty much as Mike. I do mount mine on a mandrel for roughing out and to put it in the lathe to cut the front and rear of the mounts. I'm a homeshop guy and don't have the confidence to do it all on the receiver. I do make the top and finish on the dovetails after they are mounted to the receiver.
Butch

Mike

Just curious if you have ever tried to make some one piece mounts, e.g. the bottom half of the ring and the mount being one piece, and then of course the top half of the ring.

22WRF,

Never tried it ... If you mean both mounts being made as one piece ... always wanted to top of the ejection port to be as obstruction free as possible.

I think you mean that the bottom piece of each ring has the mount made in the same piece as the bottom half of the ring. Haven't done that either. Hadn't thought of a good way to allow quick removal for a scope swap.

My entire reason for doing the thing at all was to allow my scopes to be moveable between multiple rifles ... allowing my "meager" scope supply to provide primaries and spare scopes on rifles taken some distance for a hunt.

Large caliber rifles tend to be hard on all scopes. I believe that the heavier a scope gets the greater is the likelihoods that recoil impulse with damage it (even if the scope does not slip in the rings and the mounts are indestructable) ... so if one wants to use more than a 2.5x Leupold Compact one should make arrangements for a spare.

Not quite sure why anyone would need a "fixture" to hold the model 70 receiver. There are flats on the bottom sides of the receiver that fit the mill vise well. Put a couple of parallels in the vise and set the action on them.

When I make a set of bases, I usually cut the radius with the boring head in a block of steel of the correct length and width; the holes and counterbores are done next and the bases attached to the action. All of the rest including the dovetails is done with the action correctly positioned in the mill vise.

22WRF

You mean like David Miller does???

quote:

Originally posted by 22WRF:
Mike

Just curious if you have ever tried to make some one piece mounts, e.g. the bottom half of the ring and the mount being one piece, and then of course the top half of the ring.

quote:

Not quite sure why anyone would need a "fixture" to hold the model 70 receiver. There are flats on the bottom sides of the receiver that fit the mill vise well. Put a couple of parallels in the vise and set the action on them.

not trying to start an argument here, but read this a couple of days ago and somehow couldn't forget it.

So, WITH ALL DUE RESPECT, I can see putting a model 70 receiver in the vice on top of a set of parallels, but my question is this: What if the flats on the bottom of the receiver aren't parallel with the bore of the receiver?

When I do the dovetails, on a set for Talley rings for instance, I use a collimator and set the scope on the mounts and adjust the action in the vise so the sights will be looking in the correct place. It is very seldom I have to do this.

The bore/threads on the receivers are set up to be square with the bottom of the action in most cases.

quote:

Originally posted by 22WRF:
What if the flats on the bottom of the receiver aren't parallel with the bore of the receiver?

Then you tilt the receiver and offset the vise until it is. No problem.

I bore mine with a boring bar in the mill then dress my grinding wheel to match the same diameter that I ground the receiver. It works well for me and requires very little lapping.