HW/Weihrauch HW95 rebuild

[Bedrock Bob]

After breaking a couple new (factory) springs I finally decided to dig into the HW95.

I've been using a bar clamp for a compressor. It works but it's less than ideal. I wanted to build a jig that held all my rifles properly. I grabbed a piece of 3/8" plywood and a couple pine 2x2 and went to work.

This is what I came up with. It's a push rod that uses a couple hardwood blocks to "dog" the receiver in place. The blocks can be changed to securely hold any rifle I own.

Here is a closeup of the dogs that hold the rifle. I'll make a set for the HW97 and another for the Cometa.

And here is the problem. A splintered spring. It looks to me like heating the end of the spring made it brittle. It split down the wire. The piston end has a mean left hook. It only has a max of 3k shots through it. It's been shooting below 600 fps. for the last 1000 shots.

I'm cleaning things up and installing a Vortek kit. We'll see if that makes this little rifle shoot again...

 

[Bedrock Bob]

The seal is toast. I think it's actually perforated. No nicks but it had lots of grease on the front of the seal.

 

[rwsmike]

Your jig looks gd to me ...thanks for the photo's

 

[SpiralGroove]

Beautiful work on the spring compressor .

Mine looks like it was made out of scraps near a dump, but it's functional.

 

[r1lover]

Nice spring compressor. I made one and I secure the compression tube in place with a zip tie just so it doesn't fly up and out of there.

 

[bustachip]

Beautiful work on the spring compressor .

Mine looks like it was made out of scraps near a dump, but it's functional.

View attachment 514980

I made one similar to yours, but made a delrin cup for the c-clamp that would hold the end block, it worked, but sketchy. No longer use one with the springs I use now, can do it by hand.

 

[bustachip]

After breaking a couple new (factory) springs I finally decided to dig into the HW95.

I've been using a bar clamp for a compressor. It works but it's less than ideal. I wanted to build a jig that held all my rifles properly. I grabbed a piece of 3/8" plywood and a couple pine 2x2 and went to work.

This is what I came up with. It's a push rod that uses a couple hardwood blocks to "dog" the receiver in place. The blocks can be changed to securely hold any rifle I own.

View attachment 514923

Here is a closeup of the dogs that hold the rifle. I'll make a set for the HW97 and another for the Cometa.

View attachment 514922

And here is the problem. A splintered spring. It looks to me like heating the end of the spring made it brittle. It split down the wire. The piston end has a mean left hook. It only has a max of 3k shots through it. It's been shooting below 600 fps. for the last 1000 shots.

I'm cleaning things up and installing a Vortek kit. We'll see if that makes this little rifle shoot again...

View attachment 514921

That's a nicely built compressor. and a nasty edge on the broken coil. Seems the HW piston seals are crap..lol.

 

[Bedrock Bob]

Nice spring compressor. I made one and I secure the compression tube in place with a zip tie just so it doesn't fly up and out of there.

Thanks!

The gun is low enough in the jig and the pressure is on the comp tube...not the pivot. So I don't think there is any upward force at all. I thought about a strap over the tube or a zip tie but when I put pressure on it I could see there was no need.

I used the clamp on the front face of the pivot block on my D34. It gave me the creeps. Things were offset and there was some chance of things getting loose. That's why I decided to build the jig so I could do it right.

 

[bustachip]

Thanks!

The gun is low enough in the jig and the pressure is on the comp tube...not the pivot. So I don't think there is any upward force at all. I thought about a strap over the tube or a zip tie but when I put pressure on it I could see there was no need.

I used the clamp on the front face of the pivot block on my D34. It gave me the creeps. Things were offset and there was some chance of things getting loose. That's why I decided to build the jig so I could do it right.

I don't have any pictures of the one I built and eventually took apart, but it held the front of my 97 similar to the way you have yours in the wood blocks. But I did have a wood block screwed down on top to keep it from coming out. I didn't want any pressure on the barrel, that's why I blocked it at the front of the tube. You could use a leather belt and wrap around if needed where it sits in the blocks.

 

[Bedrock Bob]

That's a nicely built compressor. and a nasty edge on the broken coil. Seems the HW piston seals are crap..lol.

It's a strange splintered break. And a mean left hook on the piston end.

I'm assuming it's an HW seal and spring. It's been rebuilt under warranty twice (AOA). The pink plastic is a nice touch. They should make matching pink breech seals...

There was a buttload of grease ahead of the piston. When i drew it out there was blackened grease all over the seal face and on the face of the comp tube. I had to scrub it off the comp tube face like a cast iron skillet.

The gun didn't diesel too badly. A little whiff every shot. No detonation but there was obviously a fire in there. The seal isn't burned through but almost. There is a super deep pit across from the transfer port like a hot nail burned a hole. The entire face has eroded 1/8".

The good news is I can't find any wear anywhere. You can hardly see the wear on the piston. Zero in the tube. I'm sure this kit will be a heck of an improvement.

 

[Bedrock Bob]

I don't have any pictures of the one I built and eventually took apart, but it held the front of my 97 similar to the way you have yours in the wood blocks. But I did have a wood block screwed down on top to keep it from coming out. I didn't want any pressure on the barrel, that's why I blocked it at the front of the tube. You could use a leather belt and wrap around if needed where it sits in the blocks.

No pressure on the barrel at all. The blocks hit the comp tube. Not the pivot block.

I hear you on the safety strap. With a long spring it might be wise. With this gun there isn't any chance of it getting loose. It's low under the jaws and if anything the pressure is pushing things down into the clamp.

 

[bustachip]

It's a strange splintered break. And a mean left hook on the piston end.

I'm assuming it's an HW seal and spring. It's been rebuilt under warranty twice (AOA). The pink plastic is a nice touch. They should make matching pink breech seals...

There was a buttload of grease ahead of the piston. When i drew it out there was blackened grease all over the seal face and on the face of the comp tube. I had to scrub it off the comp tube face like a cast iron skillet.

The gun didn't diesel too badly. A little whiff every shot. No detonation but there was obviously a fire in there. The seal isn't burned through but almost. There is a super deep pit across from the transfer port like a hot nail burned a hole. The entire face has eroded 1/8".

The good news is I can't find any wear anywhere. You can hardly see the wear on the piston. Zero in the tube. I'm sure this kit will be a heck of an improvement.

Should be better. I'm pretty sure those are the newer style HW seals, and every one I've seen on different posts are in similar disrepair..lol. Must be all the grease blowing a hole through them.

 

[Bedrock Bob]

Beautiful work on the spring compressor .

Mine looks like it was made out of scraps near a dump, but it's functional.

View attachment 514980

Mine was made from scraps left in the desert where I shoot! An old treated 2x6 about 2 feet long and plywood from a chicken coop.

The dogs are maple from an old coffee table I scrapped. There is a chair glide from one of the legs for a button and some scrap leather from a previous project.

The only thing I bought was the clamp. You could use a standard 3/4" pony pipe clamp but I decided the bar clamp would be the best platform to start with. I think I paid $50 for it. That's not much more than a set of pipe clamps and a threaded pipe anyway.

 

[bustachip]

No pressure on the barrel at all. The blocks hit the comp tube. Not the pivot block.

I hear you on the safety strap. With a long spring it might be wise. With this gun there isn't any chance of it getting loose. It's low under the jaws and if anything the pressure is pushing things down into the clamp.

When I was loading the hornet spring in my 97, if it would've got loose, it would've killed me before taking out the garage door. Getting the threads started with that thing compressed in the tube was hairy. Definitely wear eye protection.

 

[Bedrock Bob]

I don't have any pictures of the one I built and eventually took apart, but it held the front of my 97 similar to the way you have yours in the wood blocks. But I did have a wood block screwed down on top to keep it from coming out. I didn't want any pressure on the barrel, that's why I blocked it at the front of the tube. You could use a leather belt and wrap around if needed where it sits in the blocks.

Yeah the 97 is going to be different. You need to twist and manipulate things. The dogs will be 2" longer and rounded to fit the contour of the receiver. Then I'll clamp them to the rifle with a hand clamp. I'll build a little different "button" for the movable jaw that rotates so I won't be fighting friction. Those chair glides work great. Maybe put one inside a pvc pipe fitting so I'll have a shallow cup to cradle the plug.

The 97 is shooting great. I'm in no hurry. I need to get this 95 shooting again and then re seal the cometa. Then I'll make some dogs and fittings for the 97. It will be easy now I have a fixture I can adapt to each rifle. I routed out the front of the jig to fit the various "moderators" so it's just a matter of making the little dog blocks and adjusting the clamp for length.

 

[bustachip]

Yeah, you will want a cup to hold the end block from squirming side to side, when screwing it in under spring tension. I machined one out of delrin to fit the acme screw on the c-clamp.

 

[Bedrock Bob]

Yeah, you will want a cup to hold the end block from squirming side to side, when screwing it in under spring tension. I machined one out of delrin to fit the acme screw on the c-clamp.

I get it. When I realized it was a threaded pipe plug I was flabbergasted. If you had any friction on it it would want to walk out of the clamp when you turn it.

I cut a little block with a step in it to hook over the clamp jaw. Then put a chair glide on it. It will work dandy for everything but the 97.

I'm going to cut another one a bit larger than that. Then set a chair glide inside a pvc pipe cap and screw the whole shebang to the clamp jaw right through the middle. It will rotate but be held on center. In my mind it will work perfectly. But I'm still wearing my face shield and blizzard proof coveralls when I work on that rascal.

 

[bustachip]

I get it. When I realized it was a threaded pipe plug I was flabbergasted. If you had any friction on it it would want to walk out of the clamp when you turn it.

I cut a little block with a step in it to hook over the clamp jaw. Then put a chair glide on it. It will work dandy for everything but the 97.

View attachment 515000

I'm going to cut another one a bit larger than that. Then set a chair glide inside a pvc pipe cap and screw the whole shebang to the clamp jaw right through the middle. It will rotate but be held on center. In my mind it will work perfectly. But I'm still wearing my face shield and blizzard proof coveralls when I work on that rascal.

As long as that block doesn't move from the clamp jaw would be my only concern.

 

[A.G.R]

Just fallowing.

 

[Hateful McNasty]

The seal is toast. I think it's actually perforated. No nicks but it had lots of grease on the front of the seal.

View attachment 514926

Lol..ya slamming the transfer port hole

Loose sealing / piston or breech or loose / too light pellets / need more back pressure to cushion the stroke before it slams . ,( opinion)