October 29 Miscelaneous What-Nots

Numero Uno:
Just a couple quick projects today that I've been meaning to finish.
















Added a set of Uncle Mike's sling swivels to the Benjamin Sterling HR-81.  No pics of the install.  Just had to drill a hole. (Of course, there was a bit more to it than than, but only due to my agonizing about getting the hole properly centered.)

 Used kit #1071-2.  The cocking lever measured 0.432" in diameter.

Found that the supplied 3/32" allen wrench in the Uncle Mike's kit was a bit undersized. Threw it away and found one in the tool box that fit substantially better.  Helpful tip installing the band:  Get the hollow, flat head screw where you want it first, then snug down the upper allen head screw to lock it in place.  If the band rotates slightly when you load the sling (some barrels are hard to get a grip on due to high polish), sandwich a small piece of 320 to 350 grit emery paper between the barrel and clamp.  Put the abrasive side facing outward against the clamp.  Cut the emery paper just smaller than the clamp so it's completely invisible.

Also wanted a better sight on the Sterling ever since I saw Precision Airgun owner, Chuck's, personal HR-83 wearing an Anschutz diopter.  It made my Beeman (Williams made) target sight seem somehow, you know, inadequate.  Even with the old, adjustable Merit aperture, it wasn't quite what I envisioned. Attempting to do this without spending any money,  I scrounged around the parts bin, and came up with the recently removed diopter from the Tech Force TF-79.

This particular sight made the cut because it would clear the radius on the top of the Sterling.  The only problem was the dovetails on the sight body were too narrow by just a few thousandths.

Set it up in the milling machine.

Barely kissed each side with a 60 degree cutter.

Was a very snug fit--almost needed to tap it on.   Probably still fits the TF-79.

Project dos:
The other project was making a jam nut for the chopped down IZH 61 rifle.  Wanted to try a standard M-16A2 rifle flash hider, but when tightened down, the slots didn't center up.


























No pics of the process,  it was simply a matter of drilling a piece of steel, milling two wrench flats and threading it.  OK, actually did have to make the 1/2"-28 tap from a piece of tool steel...




















Jam nut screws on first, followed by the flash hider.  Align the flash hider then tighten it against the jam nut.  Done.

More soon.

An Extended Magazine Catch for the IZH 61

Still playing around with the short-barreled IZH 61 rifle.
















Unless you use some kind of riser adapter, adding either a scope or red dot severely limits access to the magazine release tab on top of the receiver.

There's about half an inch of clearance.  Probably fine if you're a six year old, but I can't seem to change magazines without some effort.

Off with the dot.

Small pin punch.  The pin comes out left to right.

Looks simple enough.  The bar pivots as the bolt is retracted and the 5-shot magazine advances until it's caught by the front bevel.  It's clever in its simplicity.

Lacking a better suited piece of raw material, I found a chunk of angle iron in the scrap box.

I should mention that this was an off-the-cuff project.

Two minutes (or less) with a hack saw.

Some eyeballing and more hacksaw and I'd rough cut the point.  The point at the bottom rides against the loading bolt.  As the loading bolt moves forward to load the pellet, the angled edge of the point lifts the magazine release.  The mag doesn't move sideways (yet) because the nose of the bolt is already going through the magazine as it loads the first pellet into the breech.  After firing, while the gun is being cocked a second time, the loading bolt retracts and when it clears the rear of the magazine, the magazine is pushed left under spring pressure. When the bolt is pulled far enough backward, it clears the point on the bottom of the catch. The catch pivots downward under spring pressure and catches the next index ridge on the top of the mag after it's moved left far enough to index the second shot.  It's a lot going on in a few fractions of a second.  

Used the mill to get the piece closer to size.  This was done entirely by eye against the stock part.  Here, I'm removing the radius on the inside corner of the angle iron leaving a ninety degree edge.

Had to thin the catch to fit the slot in the top of the receiver. 

 Cut the slot for the spring.

And eyeballed the forty-five degree angle on the front to catch the magazine index ridges.

Drilled the pivot pin hole.

And did some test fitting.  Filed it to length.  Also needed some additional clearance under the catch so it had more travel.

This was done by hand with a file.

Still in the rough.   Here it is compared to the original.

After getting it to function and actually cycle the magazine, I hand filed the lever portion.

Got to here, then sanded the top and sides of the lever to 400 grit.

Blued with Van's cold blue.

Installed.  Was going to serrate the top, but it seemed like...overkill(?)

Re-mounted the red dot.  Clears the sight.

And projects far enough on the right side.

Good clearance to the magazine housing.

An easy reach without breaking my grip on the gun. Many five-shot mags later without a single hiccup, it works perfectly.


 More soon.

Another S&W 78G

A friend made me a good deal (I fixed several of his computers for him as a favor a while back) on a S&W 78G he picked up at a gun show.

The box.

Side

Side

Side. From the Bangor Punta era.

All the documentation was there.

Not the original powerlets, but the original pellets.

Relatively unoxidized.

Pellets…

The pistol has some paint issues on the “slide”.

The grips also have a white coating.

Vintage powerlets with the bottle cap.

Paint problems.

I used a magnet to remove the power adjuster rod. Unlike the previous one I worked on, the sleeve did not slide out. Darn.

So I took some stainless steel tubing I had laying around and countersunk one end.

Fitted a long screw and trimmed the head undersize.

Added some slots.

An internal wrench of sorts. I held the tube with pliers and turned the nut to grip.

Held the end in a vise and gently whacked the slide with a soft face hammer.

And the tube came out.

Pile of pistol parts.

I discovered that the piercing pin was sheared off.

Only way to grip the pin was in a 5C collet as the large end would have fouled against standard chuck jaws.

Made it pointier without reducing any of the remaining length.

And it pierces fine.

I have one useful tip – holding the trigger down with a zip tie makes reassembly much easier.
I did run into some difficulty though, the pistol had no power. I tried a number of different solutions, lighter valve spring, lubing the hammer, triple checking that the transfer port on the barrel was aligned, replacing all o-rings (I had already replaced the dead original o-rings), etc. Then while reviewing my previous article I realized that I had made the seals from 80 durometer polyurethane rubber instead of the 95 durometer I had used the first time I resealed one…so a new valve seal was made and the pistol functions perfectly. Amazing what a change in hardness makes. I can now disassemble and reassemble this pistol blindfolded.

I’m probably going to clean up the slide and repaint and I’m thinking of making a .20 cal barrel for it as well. Given how long I’ve been taking between posts* we’ll see when that gets done…

*kids & work get in the way these days…