Monday, September 26, 2011

Frank B's FWB 124 Tear Down and Rebuild Part 1

Amazing.  After over five hundred posts on airgun butchery, we've never torn down a Feinwerkbau 124.  Nick and I both own 124's, yet still nothing on one of the most iconic spring guns ever made.

Luckily for us, airgun purveyor, rock legend, and hall of fame co-chair, Frank B, happened to have a 124 that needed some attention--and he thought it was high time to set this blog to straight.  We also figured I needed the practice and a couple more blog posts.

Frank separated the barrel/breech block assembly from the gun for ease of shipping in a shorter box.  Many folks would be hard pressed to reassemble a spring gun if they had to re-seat the cocking lever and install the barrel pivot bolt while fighting the detent spring.   So maybe keep that in mind if you're packaging something up for sale.

You know I was stuck right here until I popped the entire sheet.

The stock is one used just for shipping--we were mainly concerned with protecting the trigger.  I'm contractually obligated to disclose that Frank had absolutely nothing to do with refinishing this poor piece of wood.

Removed the stock screws and set the lumber aside.

Reinstalled the barrel assembly to the compression tube.  This is where the tear down really begins.

This is one of the few guns that I gotta use a spring compressor to disassemble.  The chunk of wood bearing against the end cap is relieved to clear the safety lever. 

An 11mm wrench fits the lug.  A slight amount of pressure on the end cap takes tension off the lug.  It should unscrew pretty easily.

As the end cap is backed out, the safety falls out along with the trigger return spring.

The return spring is directly above the trigger blade.   It pulls right out.

Roughly 4.5" of factory spring preload.

Weird.  Hey, uh, where's the grease? 

Like it's right out of the parts washer.  Where does he find this stuff?

The trigger is unitized into the end cap with the spring guide.  Also squeaky clean.

Removed the lock screw from the pivot bolt.  It works by expanding the end of the pivot bolt in the threaded hole.

The pivot bolt was unscrewed.  Note the expansion slot.  One on the opposite side of the bolt, too.

A single pivot washer on the right side of the breech block.  Note the counter bore machined into the breech for the washer.   Anyway, with the pivot bolt removed, the barrel assembly is pulled free--the end of the cocking lever also comes right out of the cocking shoe.

The piston still won't come out quite yet.

The rear of the cocking slot is enlarged to permit removal of the cocking shoe.

Remove it....

and the piston will come out.

Still no grease.  Maybe someone soaked the gun in a vat of kerosene before sending it out.

There's a tiny nick in the seal--no doubt it was cut on the cocking slot. 

No grease inside the piston body, either.  Why would someone tear the gun completely down, replace the seals and then reassemble without even using axle grease?

Not sure what's going on with that breech seal either. 

I don't think this is any good.   Fortunately, Frank thought ahead and included several Maccari parts for reassembly.  I think he sent the "Pro-Mac kit".

Give me a couple more days and I'll finish this up in part 2.


Anonymous said...

I can't imagine the time it takes to do all this....When do you sleep?

derrick38 said...

Hmmmmmmmmmmm......I don't remember.

Ryan said...

"airgun purveyor, rock legend, and hall of fame co-chair, Frank B"

Ok, so the only "rock legend" I know, who's first name is Frank, and who's last name starts with a "B" is Frank Black. What's the reference to "hall of fame co-chair?"

The joke's too esoteric for me I guess. :-)

derrick38 said...

I was goofing with Frank. He's one of those guys you're just amazed by when you talk to him and find out about his life.

Anonymous said...

Any idea how much this gun is worth? I'm trying to sell one from my husband's collection. g. abel

Anonymous said...

If my FWB-124 is needing this repair, do you still do this? Mine seems to cock ok and when pulling the trigger, seems to function as always. When I cock to reload, my pellet is still there. Weird, and I'm confused as to what is happening

Anonymous said...

I disassembled my FWB-124 which I owned since new and it was just like in the photos, no lube what so ever. Beeman recommended chamber lube which was like an oil and you placed a few drops in the chamber and worked it in with cocking the barrel a few times