Friday, January 22, 2010

A NOS Weihrauch 35 E Gets an Overhaul Part 1

Nick has been posting like a fiend lately. I think he's making up for lost time in December. I've been on an acquisition spree of late--Walther LG 55, Crosman MK2, Sportsman QB77 and this--a new, in the box, .177 cal Beeman/Weihrauch 35 EB from 1985. The model 35 has been in production since 1951 and incredibly, it's still available today. Until the introduction of the Feinwerkbau 124 in the 1970's, the 35E was one of the most powerful airguns in the world.

Beeman used to sort the guns. For a small premium, you could get a nicer stock, less barrel droop and/or a gun with a better test target. This one indicates on the end of the box that it has a "select group" meaning that the test target was in the top 10% for accuracy. That "EB" suffix? I think that the "E" refers to a more expensive stock with a raised cheek piece, while the "B" certainly stands for "beats me?"--It may refer to the barrel length.  The box was postmarked in December of 1985, so I was a sophomore in high school. UPDATE: My Weihrauch expert, Volvo, tells me that the "E" simply stands for "export". Thank you, sir, for the correct info!

Typical Beeman packaging. Volvo also noted that Beeman sorted and re-boxed the HW guns like this then double boxed for shipping. Odd, since this box has a postmark on the outside. Gun is pretty well supported in the box and difficult to remove. While it's probably considered collectible in this condition, they're still available new. This one has a serial number of just over a million.

Extra front sight inserts are hidden under the hang tag.

The guns are packaged with a factory fired test target that is serialized to the gun.

There's no chisel detent for lock-up--it's an old-school barrel latch. Press the lever forward to unlock. It's smooth and positive. The notch in the stock is necessary to allow clearance for the latch while cocking. I can't think of another current production rifle with a latch. A seriously cool feature.

Ah, the Rekord trigger.

Not a bad chunk of lumber considering this isn't a "select stock".  Doesn't look like the beech stock I expected. This is a piece of European walnut.

I fired the rifle a grand total of 3 times before setting it aside for a few days until it could be overhauled. The vibration, rattling, twang, noise, smoke--did I mention vibration?--was likely the result of 25 years sitting on a shelf. Sorry, nope, no chrony data. I found some time this morning to begin the rebuild.

Removed the trigger guard and the forend screw. Note the lack of a cocking lever slot in the forend. The rifle uses an articulated cocking linkage. The HW 50 was another classic with that feature. In theory, there is less stock vibration.

Mainspring looks really dry.

The articulated cocking link has a small housing that keeps the lever parallel to the compression tube while cocking.

Anyway, once the stock was off, I removed the sights and knocked the 2 pins out that hold the Rekord trigger unit to the tube. Used a small brass drift. Trigger comes right out. There's no trick to it at all. The safety and spring pop right out once the trigger is removed.

No grease on the mainspring, but plenty in the trigger. At least HW greased the trigger where it mattered. The sear contact is loaded with it--but it's old and waxy. Used some spray degreaser and Q-tips to remove all the old waxy goo.

Ended up here. Cleaned and lubed with a bit of moly grease on the sear.

Dropped the gun into the mainspring compressor and started to unscrew the end cap.

That's it. No pressure left from the spring. About 2"+ of spring preload.

Spring, spring guide and the giant end cap. The spring is 9" OAL and has 27 coils of 0.144" wire diameter. It's approximately 0.909" in OD. The spring guide is noticeably undersized at 0.552" diameter. That's just, uh, fantastic. The guide rattles inside the spring and the spring rattles inside the piston bore. Guess that's why they used to use an entire jar of moly on airgun tune-ups. Took up the slop and acted as a damping medium.

The end cap is absolutely massive compared to that on most spring piston guns. The end cap weighs 13.7 oz. Over 3/4 of a pound of steel. Remember Beeman's "Tap the Cap"advertising?

Polished the front end of the cap just enough to take off any high spots.

The spring guide seats against this end. A smooth finish may allow some guide rotation to help cancel spring torque. It's sure not gonna hurt for 2 minutes on the buffing wheel.

Removed pivot locking nut on the right side and the lock washer.

Then unscrewed the pivot bolt from the left side. It helps to break the action to take the pressure off the latch (or detent if it's a typical break barrel) then remove the pivot bolt. Otherwise, the bolt has some pressure on it from the latch spring.

Pulled the bolt free and fished out the razor thin pivot washers. One on each side between the breech block and the tangs on the compression tube.

Another pic of one of the pivot washers. There's the barrel latch.

The breech block came free and the barrel latch fell right out. Note the spring in the block that presses the latch rearward for lock up.

The barrel cocking lever assembly came right off. Fished the round end of the cocking lever through the hole in the compression tube.

Only the piston remains inside the tube.

Hooked end of the piston rod with a flat blade screwdriver and pulled it from the tube. Wiped off the grease and here it is. Older HW 35's use a leather piston seal. HW 35's with serial #843636 and higher use the synthetic seal.

The small circle on the face of the piston seal is from the transfer port hole. 25 years of pressure will do that to you.

Pried the seal off the piston head. Still feels pliable and has good elasticity. It also appears to match a spare Beeman R1/HW 80 seal found in the parts pile. I'll use it in the reassembly and see how it shoots.

More coming soon.

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