A Great ARH/JM DIY ...
 

A Great ARH/JM DIY Tuning Option for HW77-97-R9-HW95-85-R10-11 Owners---Get 'Em While They're Hot!  

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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2018-11-28 22:38:18  

(Edted: re Old and new HW77, and seal info).

Hi guys, I know that many of you own one of the above rifles, and do some of your own tuning work.  So, I wanted you to know that there's a nice spring kit tuning option on the ARH/Maccari site right now for only $35.  You get an upgraded spring PLUS a custom-fitted synthetic front guide:

http://www.airrifleheadquarters.com/catalog/item/8000185/10394208.htm

I got mine yesterday.  This spring will give you good FAC power in all of the above rifles.  The spring kit will fit both old and new Hw77 models.  IMO this was never meant to be a 12 FPE spring.  You need to pick the right piston seal based on which rifle you have if you need a new seal.  (Was there also an old version of the HW97?--I think maybe there was, but, honestly, I just don't remember).

The power potential varies a little in the R9, R10, etc, and newer HW77, based on which piston seal you choose.  

No matter which rifle you have, the spring and front spring guide help eliminate some spring twang.  You use your existing factory rear guide.  The spring comes already set for easier installation.  This is from the site:

"Kit includes a custom spring and a long forward guide with a sample tar.

"Drops in on your rear guide and the kit is preset.

"The spring fits the OEM guide nicely".  (He means the rear guide--there is no OEM front guide).

If you have an earlier steel factory rear guide like the one that came on the R10, etc, the fit is pretty-decent--just use a little extra spring tar on the OD of the guide.  If you have the synthetic factory rear guide that later came on many of these rifles, the fit is almost-perfect. 

When it comes to piston seals, if you have the older HW77, it takes a 25 mm seal like this one:

http://www.airrifleheadquarters.com/catalog/item/251485/1381148.htm

If you have a newer HW77 or the other rifles listed, they take a 26 mm seal.  You can buy a flat-faced version like the factory seal, or the Hornet seal for a little more power.

Flat-faced 26 mm seal:

http://www.airrifleheadquarters.com/catalog/item/251485/9946364.htm

If you want all the power the kit can give you, but still with a pleasant shot cycle, use the concave-faced 26 mm Hornet seal.  Or, you can leave it sized on the tighter side for less than maximum power and a calmer shot cycle:  

http://www.airrifleheadquarters.com/catalog/item/251485/1151533.htm

I don't know when I'll have a chance to use this kit because I'm supposed to have some tuning work coming very-soon.  We'll see.  

Anyway, you might want to jump on this while it's in stock.  You can always save one for a 'rainy-day project'. Remember to check your breech seal, too.

HTH.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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desertplinkerforlife
(@desertplinkerforlife)
Joined: 2 years ago
Posts: 36
2018-11-29 09:01:09  

thanks for the heads up, although I am no tuner but like to have JM stuff around just in case, was thinking on the 77's I guess this would be for newer models?


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ekmeister
(@ekmeister)
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Posts: 448
2018-11-29 10:55:18  
Posted by: desertplinkerforlife

thanks for the heads up, although I am no tuner but like to have JM stuff around just in case, was thinking on the 77's I guess this would be for newer models?

You asked a very good question. I didn't think about qualifying my answer to address the difference between the old and the new HW77 in regard to the difference in the size of the piston seals.

1. The spring kit will fit both the old and the new 77.

2. The piston seal situation is different.  The Hornet seal I listed is for the newer 77, that takes a newer 26 mm piston seal. 

But, if you have the old 77 it requires a 25 mm piston seal. You can buy those at ARH, too, in the piston seal section.  Here's the link:

http://www.airrifleheadquarters.com/catalog/item/251485/1381148.htm

That's a 25 mm seal. It doesn't have the same concave face shape as the Hornet seal with its slight edge in power.  Instead, it's basically like the flat-faced factory seal.  It DOES have a rear wiper on the side of the seal to help deal with the possibility of excess lube in the chamber, and it also holds a little lube to renew the lubrication of the seal over time.

Thanks for jogging my memory about this.  I wrote the post kind of late last night, and obviously not all of my cylinders were firing.  I think I'll go back and edit my previous post so I don't confuse anyone else.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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Jeff P
(@pad617)
Joined: 2 years ago
Posts: 52
2018-11-30 19:02:54  

Funny, I just replaced the spring and seals on an older 25mm piston HW77 with some JM parts.  This one is set up for a 12 ft-lb FT rifle.  It uses JM's E3650 Ultra spring (.120 wire) and his 25 mm seal.  I used a new HW breech seal.  I had an older nylon rear guide that almost fit so I chucked it up in my drill press and sanded it down to a snug fit.  I also had a front guide in a parts bin and sized that down to fit.  Only thing I really messed up on is not having the spring set by JM.  Its a fairly long spring and even with a spring compressor it's a little daunting to stuff in there without having it pre-set.  I was able to do it using a threaded rod and some nuts but it wasn't ideal.  I made a setback trigger blade from some 1/4" aluminum and scabbed it onto a factory blade.  Anyway turned out ok considering my skill level.

parts

seal

trigger group

chrony

Jeff P

 

 


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stevevines
(@stevevines)
Joined: 2 years ago
Posts: 148
2018-12-03 05:44:22  

I too would like to thank Ed for the heads up. I just purchased the HW 95 and Hornet seal kit for my R9 as a birthday gift to myself, as today is the 41st anniversary of my 21st birthday.

I've never worked on a Weihrauch - is it anything like working on a Diana M34? Do I just remove a couple of pins going thru the trigger group? Probably need a spring compressor? Maybe that question would be better for a new thread?

Anyhoo,

Thanks again Ed!!

 

 

 


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desertplinkerforlife
(@desertplinkerforlife)
Joined: 2 years ago
Posts: 36
2018-12-03 15:15:20  

Great job Jeff. And Ed. Talk about an enabler! I bought a 77 from Krale and the JM tune kit to go with it.         

weihrauch hw 77


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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2018-12-03 18:47:13  
Posted by: stevevines

I too would like to thank Ed for the heads up. I just purchased the HW 95 and Hornet seal kit for my R9 as a birthday gift to myself, as today is the 41st anniversary of my 21st birthday.

I've never worked on a Weihrauch - is it anything like working on a Diana M34? Do I just remove a couple of pins going thru the trigger group? Probably need a spring compressor? Maybe that question would be better for a new thread?

Anyhoo,

Thanks again Ed!!

Is it anything like working on a M34?  Well, I'm not being facetious when I say, "it's kind of the same, only different".  If you can work on the 34 without a spring compressor, you should be able to handle the HW95, too.  The amount of muscle you need is pretty-similar.

The retaining system is 4 or 5 small squares through the spring-retaining cylinder instead of 2 cylindrical pins.  Study it over before you actually start taking it apart and that should help.  Also, have a short piece of 1" dowel rod and a dry washcloth (to push down on the dowel after you give the trigger housing/ spring-retaining cylinder a slight twist) at the ready.

And, you're welcome!!

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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