Friday, July 31, 2009

George's Sheridan Stock

George is mainly into firearms but he does own a transitional Benjamin-Sheridan Silver Streak. He brought it by "open shop" the other night to show the stock he made for it.

What do you think?

He fabricated the trigger guard.

That wood! It's even better in person...

He extended the forearm to provide more leverage.

Recessed stock screw. Most guys wouldn't think to wrap the forearm around the stock like that.

Inlet entirely by hand.

The trigger guard is perfect.

He used three roll pins to attach the forearm.

George is intent on selling it and I'm severly tempted.

Tuesday, July 28, 2009

Fabricating a Replacement Front SIght for the Slavia 630, Part 2

On I go.

Drilling some 5/8" diameter bar.

Reaming 1/2"

Soldered (silver soldered) the two parts together. Notice the large area of solder overun...things shifted a bit while they were red hot and I was poking solder into them.

Cleaned up.

Drilling for the sight post.

Tapping #8-32

Turning down the end of a #8-32 setscrew to make the post.

Facing the end.

Tapping #4-40 for the clamp screw.


Another lame cold blue job by yours truly. The upside is that I can now shoot the air rifle and hit what I'm aiming at, which was the whole point of this little exercise...

Monday, July 27, 2009

Fabricating a Replacement Front Sight for the Slavia 630, Part 1

I finally got to work making a replacement for the missing front sight on the Slavia 630.

My question was, what is the dovetail angle for the front sight? So I measured over some PeeDee thread wires. Then I repeated the measurement with a 2nd set of different diameter wires.

Here's the result. By drawing the diameters and distances of the wires I was able to draw a line tangent to the two circles (the thread wires) and measure the angle. I also did a bunch of math based on the Machinery's Handbook formulas for measuring dovetail slides, using the pair of measurments to solve the unknown "a" and then using that value to solve for θ. I shouldn't go into it as it's a tad boring. But it is fun if you like math...
x[distance over wires]=D[diameter of wire](1+cot 1/2θ)+a
Which means that ((x-a)/D)-1 = cot 1/2θ
So ((x1-a)/D1)=((x2-a)/D2)
Solve for a...

The dovetail angle is likely 60 degrees and the measurements were thrown off by the small magnitude of the measurements, burrs, etc...

Oh right, I'm getting ahead of's the old rear sight.

Now with a new thin rubber pad...

Here's my first attempt at making the sight, milling from solid with a rotary table.

I found the finish and result to be less than ideal. Not sure if the mandrel was flexing or I need to read up on peripheral milling. In any case a good experiment but a poor job...

So now what? I drilled and tapped the end of a 3/8" diameter bar with a #10-32 thread.

Using my fancy center finder.

On center.

Drilled then reamed 3/16"

A small cutter was ground from a broken 3/16" shank endmill and set to cut a 5/8" diameter circle as it revolved, ((measurement-1/2 bar diameter)*2=cut diameter) making it a poor man's boring head.

A small block of steel was milled to the proper dimensions.


Milling a channel.

Set at an angle to mill the 60 deg. dovetail. This method is better than using a dovetail cutter (and I didn't have a proper one that size anyway) as it provides relief for the curve of the barrel.

More edgefinder fun, finding the centerline again.

I took several passes to cut the radius with my boring tool.

Nice finish. Poor man's boring head wins again.

Fits the radius gage perfectly.

And fits the dovetail (after several iterations of cutting and fitting) snugly.
More to come...