Mounting a Williams Peep Sight on a Sheridan

My uncle called me at the shop a few weeks ago and asked me to stop by on my way home.  Our mutual friend, Sandy, had kindly dropped off two Sheridan rifles for me.  We shoot firearms together and she'd heard about the airgun blog.  They belonged to her late husband, Paul, and she wanted them to go to a fellow shooter. 

Both of the Sheridans are exactly the same vintage with the rocker-type safeties.  Of course, both are .20 caliber and have real walnut stocks.  They've got the dings and dents to show their age.  They were users, not safe queens.  Of course, I'd like to clean them up a bit.  Maybe an oil finish on the walnut, add a recoil pad... Anyway, to that end, I removed the stock and pump handle from one and started to sand off some of the factory varnish in preparation for a higher quality finish.  I need to get into the garage and do some finish sanding, but this morning the thermometer read eleven degrees.  So, I turned to the second gun (in the much warmer basement).



 
No idea of the exact vintage.  1970's?

The scope is great to shoot with, but it covers the exact spot on the receiver one should grasp while pumping the gun.

It's also difficult to lift the bolt and cock the hammer.  The clearances are just tight enough to make this awkward.

Removed the scope

This'll find a home on a different air rifle.

Removed the intermount.

The original sight was also removed.  I've read that these sights can promote solder separation between the barrel and pump tube.

Took the action out of the stock.

Removed the two screws holding the cover and cam plate.

Here's the bolt lug.  It's a 1/8" allen head.

Surprised to find that I have a nut driver that small.

Use care when removing the bolt, as the bolt spring will go flying.

Bought this Williams peep sight from Chuck at Precision Airguns in Maple Heights, OH.

On the new Sheridans, the rifles are factory-drilled for this sight. On the older guns, it's up to you, baby.

The supplied mounting bolts are #6-48.

Did some layout on the breech and gently clamped the action in the milling vise.  Found a piece of brass tubing that was a snug fit in the bolt channel.  Drilling through the breech and into the tube let all the chips drop into the center of the tube rather than into the pump/valve mechanism.  Also prevented any burrs in the bolt hole.

Drilled with a #32 bit.

I actually have a #6-48 plug tap???  This was an even bigger surprise than finding that nut driver.

Installed the sight and put the bolt mechanism back together.

Took few sighters and had the gun zeroed in a dozen or so shots.  The double screws holding the sliding windage adjustment is rather crude, but the gun is substantially easier to pump and work the bolt handle.  A good trade off between precision and ease of use.  The trigger, by the way, is exceptional. 

IZH Diopter Sight Addendum

This was just an afterthought. Some of the target sights have a small extension on the windage adjustment for easier purchase. Each knob is attached with a small set screw. I simply removed the setscrew on the windage knob and measured the thread size, then found a suitable piece of steel rod.

Cut and faced a piece of 0.125" drill rod. Turned down one end to 0.118".

With a mill file, I rounded the end.



And tapped to M3 x 0.5mm. Actually didn't need a die handle--small, fine threads are that easy to cut.



Slotted with a hacksaw blade. The blade was modified--the offset was ground off so the blade cuts to it's true width. Handy for small screwdriver slots...

...on small screws.

The mill file came out again and rounded the head.

Blued.

Installed.

Done. Took about ten minutes.

An Aperture for the IZH Diopter Part 2 Final

Right back at it.

With the 1mm drill bit broken off flush in the aperture...

there was really nothing to do but drill it out with a solid carbide bit. Now the aperture had a giant hole. Lots of light! No sweat. I'll plug the hole and try again.

I opened the hole up a a little more with a #3 bit (my tapping size) and tapped the hole 1/4"-28.

Faced off a scrap of 0.250" diameter acetal (aka: delrin).

Cut a screwdriver slot.

threaded the outside 1/4"-28.

Chopped off a small section. Click the picture to enlarge it and it's easy to see the 1/4"-28 threads in the aperture disc.

A screwdriver from the front threads the acetal into the aperture. And I'm back to where I started before breaking the bit.

The acetal is in really snug and barely stands proud. It's not going to move under recoil so I don't have to worry about it vibrating out.

Faced off the acetal.

Spotted.

Lets try this again. Found another 1mm drill bit and through drilled the plastic plug.

The soft acetal was easy on the bit. Made a second pass at a faster speed. Wanted the hole as round as possible.

Blackened the face of the aperture with some Birchwood Casey Aluminum Black to minimize reflection/glare.

Blackened the inside of the through hole as well.



Test fitting.

Eye shade



All the clearances look fine. I'll paint the outside of the aperture.

A second piece of the threaded acetal rod was cut off, faced, slotted and spotted...

And through-drilled with a 1.2mm drill bit.



So, I screwed up, but ended up with a dead simple aperture with two interchangeable inserts. A 1mm and a 1.2mm.

Final shot. Wow, look at the size of that 10 ring! Just realized that these must be pretty old targets, as the scoring rings were downsized years ago.