HW 77/97 refurbish & venom tune

[Paul Hudson]

Got mine apart - and back together...

Looks like it's been blowing back past the PowerPulse seal. There's no obvious signs of damage, but the seal is a few thou less in diameter, and MUCH harder, than the standard one.

Anyway, standard one is now back in and the power has more than doubled with JSB exacts (4.51). Next step is to chrony it over a few more strings and see what it settles down to. It's currently nudging the limit with no piston weights in place.

Gibbon. Your spring is parcelled up and addressed. I'll be posting it sometime tomorrow morning.

Cheers,

Paul.

[loiner1965]

y h email paul......

[Paul Hudson]

YHM back - it's yours FOC Steve .

Now why didn't I think of that... why on earth would they change the size of the compression chamber?

Paul.

[loiner1965]

YHM back - it's yours FOC Steve .

Now why didn't I think of that... why on earth would they change the size of the compression chamber?

Paul.

thank you...now i need a lazaglide piston....and a.......lol

[RAGS]

We have no regulations in ME here in India and I have ordered a FAC spring from BAR for my HW77/.22. I don’t have access to a proper spring compressor, though I have used a scissor jack combo with some success on my other guns. The FAC spring is longer than the venom spring and it’s a nuisance to get it back into the HW action (I tried to put the original longer spring back and it was frustrating) without a proper spring compressor. Rustam has some ideas here and will attempt this when the FAC job comes in.

With Diana actions, when the spring/ trigger unit has been compressed into the action, it’s a question of putting in the retaining pin and the whole thing holds. With the HW action, with all parts compressed, the trigger block assembly has to be threaded into the action, and this can be quite testing.

Any other ideas on how to put the longer spring back, guys?

[Gibbon]

Hi Rags

I'd ordered the FAC kit too. The spring supplied was shorter than the original and the wire used is thicker - take a look here

I put 2 of the 4 washers into the piston, with everything back in place the spring was only protruding about 2cm from the cylinder. Put the muzzle down to the floor using a soft cloth to protect the finish on the silencer. Hold the trigger block in one hand and push it down to engage the thread whilst turning the cylinder with the other hand.

I was expecting it to be a lot more difficult ! Sure, it needs a bit of effort, but not a huge amount ... certainly not enough to warrent using a spring compressor (I'm a puny weakling BTW)

Good luck

ps. Paul H : thanks once again mate, you're a star

[RAGS]

Thanx Gibbon ! Which means the FAC replacement will be fairly easy!

And your 'Location' - That was Revenge of the Pink panther , right !!!!!!

[Gibbon]

Yep ! Classic scene where Cluseau is questioning the guy with the monkey whilst a bank robbery is going on in the background

[Paul Hudson]

Just got back from the PO mate. Sent the spring 1st class par avion. Not sure how long it'll take, but let me know when it arrives .

Just an update on my own 97K. Loiner very kindly (and gently) reminded me that Weihrauch changed the size of the compression chamber on the 97K. It seems that I've got a kit for an older version, hence the blowback problem.

One of the guys from our club is ordering a kit for his 80 this week, so I've asked him to add a piston seal for my rifle to his order .

What I will say is that it is almost as smooth as my Venom Target Trophy now. Not sure how long it will be before I give in to the temptation and send it off for the full treatment though... .

Paul.

[Hsing-ee]

have you got the right kit? HW77s come in two varieties, one with a wider piston chamber and one with a narrower.

just a guess.

[Paul Hudson]

Erm... isn't that what I just said IS the problem?

Paul.

[Martin]

Paul, it would be interesting to see how the stage 1 HW97 feels like next to my SFS HW98, not exactly a straight comparison, but it should give a good indication, i still trying to get rid of a bit of creep on the 2nd stage of mine, its predicable enough though

Regards

Mart.

[Hsing-ee]

Erm... isn't that what I just said IS the problem?

Paul.

whoops! that'l learn me to read Page 2 of the thread. good luck anyways.

[Meerkat]

Gibbon,

the only error in DaveL's instructions concerns the thin sleeve that goes into the piston.

"After ensuring the piston was clean inside, the piston liner was inserted in accordance with Venom's instructions, with its gap in line with the centre of the piston slot, but I didn't push it all the way in - I left about a centimetre of the thin liner projecting from the piston."

The slot in the liner should be 180 degrees from the cocking slot in the piston, not in line with it. This is to stop the grease getting out and in front of the seal.

Steve

[Paul Hudson]

Paul, it would be interesting to see how the stage 1 HW97 feels like next to my SFS HW98, not exactly a straight comparison, but it should give a good indication, i still trying to get rid of a bit of creep on the 2nd stage of mine, its predicable enough though

Regards

Mart.

I'll throw mine in the car and bring it to the shoot at Redfearn in a fortnight. You can try them back to back.

Cheers,

Paul.