Monday, January 25, 2010

A NOS Weihrauch 35 E Gets an Overhaul Part 3

Almost ready to reassemble the HW 35 E . Just a few things to deburr and polish first.

The cocking slot on the bottom of the compression tube always has some really sharp edges.

A small file, a diamond hone, sandpaper whatever. I used a deburring tool this time. Be careful, the edges of the slot or the tool itself can open you up like a zipper.

I hit both the inside and the outside edges. This makes the gun smoother to cock and reduces the chance that the piston seal will be damaged upon reassembly.

Finished with a rubberized abrasive block. It's called a "Rust Eraser" or something like that. Cleaned the tube thoroughly inside and out after this step.

Polished the end of the barrel latch,

and the end of the cocking lever.

Then cleaned the barrel with the JB Non-Embedding Bore Cleaner.

Some moly grease on the end of a plastic dowel

And gave the compression tube a very thin coat.

Also slathered the piston--inside and out. Didn't lube the front of the seal. I wiped this down to a thinner layer before sliding the piston into the compression tube.

Like so.

Lubed the barrel latch spring in the breech block.

Pushed the spring forward with an M5 allen wrench. Once the spring was far enough forward to clear the small post on the back of the latch, it fell right into place and the spring held it fast.

Installed the barrel pivot washers using the moly grease to hold them in place,

then attached the cocking lever to the piston and used a dental pick to line up the pivot washers. Installed the pivot bolt, washers and nut.

Coated the end of the cap with moly. The spring guide will bear against it and it should be free to rotate.

Very thin coat of moly on 100% of the spring and guide. Chucked it into the spring compressor and reinstalled the end cap.

Cock the trigger.

Install the safety and spring.

Insert the trigger unit, line up the holes and press the pins home. Pull the trigger--CLICK!--or the gun won't cock and you may think the spring is too long. Not that I've ever done anything like that. Never. Not even twice.

Bought this Air Arms aperture sight last week from West Virginia airgunner Scott T. He lives near some of my favorite backpacking spots in the 900,000 acre Monongahela. One of the most beautiful places I've ever hiked. Thanks Scott.

Fired about 40 shots through and set up the chrony. The gun was clocking in the 640 fps range with .177 cal RWS Hobby pellets. A bit too low even for me. The shot cycle was smooth and short with none of the earlier vibration and buzzy noise. So the first replacement spring is a bust due to the low power. It did shoot rather nicely though.

Stock removed and pulled the trigger and safety--again.

Only need to remove the end cap, spring and guide.

Turned the guide down about 0.013" to fit inside the thicker wire diameter mainspring from the parts box. The guide ended up at 0.630" diameter.

Reassembled the gun and again fired about 40 shots before checking the velocity. The rifle was noticeably faster just from the sound. The chrony confirmed what my ear told me. About 750 fps with the heavier spring. This spring is pretty close to the factory spring. Really just a bit larger in diameter. I'll check it again tomorrow and see how it does after sitting overnight.

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