Feinwerkbau 124 Sling Attachment and Scope Stop -- Part 1

This old Feinwerkbau 124 was my first air rifle purchase.  Think I was sixteen or seventeen at the time.  I'd been reading the Beeman catalogs and wanted something decent.  The R1 had come out recently and wasn't in this kid's budget, but the FWB 124D in the used gun rack certainly was.  Several decades of repairs/upkeep/changes and modifications led to its current set up.  Probably the most significant improvement was the hand made walnut stock from GunBroker.  The stock was made by Serban Ionescue.  It's a beautiful thing.  The lines are so graceful and unique.  

While shooting this the other day, I remembered I hadn't actually finished the replacement stock installation.  Sure, the rifle was shootable, but it wasn't "done".  At the time, I'd done a make-do arrangement with what used to be the built-in front sling loop and I neglected to install a rear sling stud.  I actually had a rifle with no way to attach a sling.  

And all I needed was a barrel band clamp and a screw stud?

Dug through the collection of pieces and parts, but didn't find that necessary screw stud.   A quick trip to the local "gunmart" was fruitless.  They have a Glock section, a Smith and Wesson M&P section, all the Magpul gagets and a bunch of employees who won't even pretend to help.  Was really a great experience.  Went home, ordered a ten pack off ebay and checked it off the list. 

A week later, I was awash in sling studs and trepidation.

Installing this little guy gave me great anxiety.  The stock was beautifully finished. Was I about to ruin it?   Would the stud be centered?  Will the walnut splinter, crack, and tear?  How many bad sling mounting jobs have I seen in the used gun racks at any given gun show?  

Eventually, I'd checked, double-checked, re-checked, then double-re-checked everything--especially the drill bit size.   And in a couple minutes, it was done and all my worry was for nothing.  No, that's not really true.  All my worry identified the potential problems I would run into during the installation and helped prevent them.  Catastrophizing is often my super power.

The front end of things was less of a challenge.  I found an Uncle Mike's barrel clamp for the front attachment point in a drawer--probably purchased and set aside years ago for this very project.

Just like that, the old girl was finally wearing a 1.25" Outdoor Connection Super Sling+.  While a leather sling might look more appropriate, its tough to beat the quick adjustability of the Super Sling. 

Now, here's the rest of my unfinished business. The original FWB front sling swivel had to be removed because its flared width wouldn't fit through the longer forend of the new stock.  I'd quickly installed a couple aluminum washers on either side of the rivet and said, "Good enough, I'll figure this out later". 

Here’s the removed FWB sling mount. 

The way it flares out at the bottom prevents it from fitting through the new stock’s extended forend.  The shorter factory stock doesn’t come far enough forward to be a problem. 

Of course, at the time, I was far more interested in getting the action into that gorgeous stock.  Besides, that original FWB mount was only sized for the old skinny 22mm (7/8") carry straps.

And then the plan came to a screeching halt and I opted to make a scope stop instead.  Yes, a scope stop.  Why?  No good reason, but follow the squirrely logic:  The gun shoots fine and now wears a real sling, so I can live with the aluminum washers for another day or two.  A quick and dirty scope stop sounded far more appealing.  My continued procrastination made sense at the time.   

Yep, a scope stop it is.

As the Feinwerkbau was wearing UTG dovetail mounts, I wanted the scope stop to look like it was made to match.  Found a UTG offset mount and cut off part of the clamp.

I like projects with the least amount of resistance.  (I later added another mounting hole to that sacrificial mount so it's still functional.)

Cleaned it up in the milling machine.

Just needs a second clamping screw.  I can't believe I've never made a scope stop before.  

Tapped M5 to match the other thread.

Not shown:  As conventional stop pins don't fit 124's,  I wasn't going to drill and tap for one, but the practicality of having it won out.  Now, it's compatible with most of my other rifles.

 

With no stop hole in the 124 tube, some friction paste will have to suffice.

Matched and replaced all the mounting hardware for continuity.  

A plug screw fills the hole.

Looks like a good match and I've successfully put off making a cocking lever rivet for another day!

More soon.  

#4-48 Breech Screws for Crosman

Just a quick post tonight.

The other day, I was taking apart a Crosman 2240 pistol and I thought the stupid tiny #4-48 breech screw should be replaced.  I went to my spare parts and found I was down to two.  Used to buy these screws right from Crosman, but with the Daisy/GAMO buyout, I think that option is now gone.

With all the Crosman CO2 guns around here, figured I'd better come up with a new source.

Let's face it,  #4-48 just isn't a common fastener size.  Crosman was essentially forced to use such a fine thread due to the thin gas tube wall thickness.  To make it even harder to source, Crosman spec'd a low profile head--pretty much guaranteeing that this is a custom fastener.  These just don't exist at the local hardware store/home center.

That micro 0.050" hex wrench is icing on the cake for a bad experience.   Over torquing the tiny fastener--or wrench-- is pretty much inevitable.  

Yeah, I pretty much hate this fastener.   I usually treat these screws as single use.  I'd much rather burn the dollar they cost than have to remove a stripped, stuck screw in a gun.

In an effort to solve my shortage and not have to think about this again--at least for the forseeable future--I bought a 25 pack of #4-48 BUTTON HEAD CAP SCREWS from McMaster-Carr.  

Of course, the button head is a bit too wide in diameter to fit into the counterbore in the Crosman breech.

Here's the button head vs. the low profile socket head.

 

The button head is about 0.208" diameter vs. 0.180" of the original Crosman spec.

Made one of my fancy thread holders.

And a #4 nylon washer for standoff.

The Taig lathe makes short work of problems like this.

In a few seconds, the head diameter was reduced to a functional size.  Don't need to hit the 0.180" diameter to the exact decimal.  As long as the head fits the counterbore recess of the breech, it'll work.

Since I was still feeling all fancy from making the thread holder, I blackened the head and called it good.  

As a marginal benefit, the button head fastener takes the next larger 1/16" hex wrench.  The (.0125") larger wrench size feels gigantic in comparison.

No lathe?   I just chucked one of these screws in a DeWalt cordless drill and reduced the head size with a small file in a little over 3 minutes.  

More soon.