HW/Weihrauch First Time Spring Change

Thinking about replacing the spring in my HW77. My goals are to smooth out the shot cycle and elimiNate the “twang”. I‘m looking for a soft shooting target gun, no hunting. I have not done this before and am moderately handy. What YouTube videos do you recommend? What tools do I need? What do I need to be careful of, aka watch out for? What kits do you recommend? Appreciate your suggestions. Thanks, Tom
 
your on the right track , learn all you can before you attempt anything . maybe you will need to build a spring vice /clamp . nice videos on builds but i have not found a videl doing the process start to finish taking apart . removing a spring / replacing . lots of talk but no action hahaha
i seem to remember a few people in AZ that self tune, maybe one will chime in ?
 
I only opened my HW97 once. I remember the anti beartrap being fiddly, but the details are lost to time. After drifting the pins out to remove the trigger assembly, put the handle of a crescent wrench in the slot and give it a "tap" with a hammer to break loose. The rear just unthreads. Mine is a 12 ft lb and I didn't use a spring compressor, just a heavy work glove to protect from sharp edges.

It was easier than the HW50, that one had to lean on fairly hard to be able to rotate the tab out of its slot.
 
Just search for 'hw97k/77 strip down' on youtube and you will find a number of instructional videos.


You'll need a few small and medium screwdrivers, a punch set and some type of spring compressor. I use a simple carpenter's wood clamp. Obviously, you'll need a replacement spring or drop in tune kit from Vortek or ARH, new piston seal and some moly paste. If you are going to open up the gun, might as well replace the seals too.

Key is to just take is slow and easy and not force anything. If you are using a lot of muscle, you are doing it incorrectly.

The hw97/77 guns are a pit more challenging to strip down because of the screw on end cap.

If you want a mellow target shooter, I'd suggest an ARH tune kit with the soft spring, or a 12fpe Vortek kit.

Just do some basic homework and all should go well.

R
 
  • Like
Reactions: maxtrouble
I was able to assembly a full power hw97k just by hand but it surely resisted and wasn’t easy.

The screw end cap is more difficult than troughpins for sure.

My 97k was twangy before a good cleaning and good lube job. I was amazed how the twang went away with using lubro teknik sg3 grease. Spring was very sparingly greased from the factory.

My gun has a good spring guide fit from the factory. That helps alot.
 
Firstly, I remove the anti-bear trap. Proper loading procedures make it unnecessary (always hold the lever/barrel), kind of like the warning on a ladder telling you not to rest it against electrical wires.
Second, I can highly recommend JM (ARH) for the proper spring kit. He has probably tuned more of these guns than anyone else.
Agreed, I decock my 97 and 77 quite a bit. And JM makes awesome springs.
 
  • Like
Reactions: Moog
This is what worked for me with a couple of HW95s. The HW95 has the same power plant as your 77.

I ordered springs from Air Rifle Headquarters and piston seals from Vortek. I used a dremmel on the spring guides because they were a little to wide for the new springs. The new springs now fit snug but not tight.
I got rid of the factory grease and relubed with moly paste. I used Black Tar grease on the spring. Both of these lubes are from Air Rifle Headquarters.

Now both rifles give me a nice smooth shot cycle. No buzz or twang.