HW35 Fettling

[deejayuu]

I made it the same depth as your old seal and carrier. Didn't measure the stroke.

Ah thanks! . The head/piston graft makes sense, with that info., looking again

[T 20]

I made it the same depth as your old seal and carrier. Didn't measure the stroke.

If it was originally a screw on adaptor (m8 thread) and synthetic seal it would have been about 61mm stroke, Nick.

The standard leather sealed piston has about a 65mm stroke.

The standard synthetic sealed piston has about a 69mm stroke.



All the best Mick

[Shed tuner]

The standard synthetic sealed piston has about a 69mm stroke.

All the best Mick

and that's why I love the synthetic stroked '35... tried it after Mick shared this years ago, and it just makes power so much easier...

https://www.airgunbbs.com/showthread...5-to-synthetic

[T 20]

and that's why I love the synthetic stroked '35... tried it after Mick shared this years ago, and it just makes power so much easier...

https://www.airgunbbs.com/showthread...5-to-synthetic

Bloody hell, I remembered the strokes correctly, Jon.

Another thing with the factory synthetic sealed piston is that it's machined to take more spring length inside the body than the leather sealed piston --- this is probably done so that it takes the same spring as the leather sealed piston ?

My glided, rotating 71mm stroked piston shown in that thread is in my favourite 35 build --- it makes just shy of 12ftlbs using a cut down HW50 spring.
I could only drill the piston body to 20mm ID which dictated using a Meteor, HW50 or SMK spring.



All the best Mick

[Shed tuner]

Another thing with the factory synthetic sealed piston is that it's machined to take more spring length inside the body than the leather sealed piston --- this is probably done so that it takes the same spring as the leather sealed piston ?

All the best Mick

well I never noticed that either... that'll help it shoot softer too... thanks for sharing, we've missed your insight mate

[TonyL]

Yep, brilliant information from our Mick, as ever. Great that you're managing to join us more agai these days, Mick, and contribute with your brilliant insight.

Yep, although I hadn't thought too much about it at the time, when I fitted that later piston to my other old one, preload did seem to be about the same.

[TonyL]

And, with all this insightful information, this thread is becoming what might be a most useful reference for many a current and future home tinkerer.

[T 20]

well I never noticed that either... that'll help it shoot softer too... thanks for sharing, we've missed your insight mate

Not so much an insight as an observation, Jon.

I couldn't machine enough weight off the front of a leather sealed piston to get its weight down to that of a synthetic piston, so I took a squint at them side by side.
The arbor plug in the front of a synthetic sealed piston ends about 2mm shy of the cocking lever slot, whereas the plug in the leather sealed piston extends about 8mm along the cocking lever slot --- the plug is actually milled into for the cocking lever.

[T 20]

Yep, brilliant information from our Mick, as ever. Great that you're managing to join us more again these days, Mick, and contribute with your brilliant insight.

Yep, although I hadn't thought too much about it at the time, when I fitted that later piston to my other old one, preload did seem to be about the same.

I'm always about, Tone.

Just having a bit of a nightmare balancing the drugs I'm on, and if I don't have anything worthwhile to post I keep quiet.

I'm still fascinated by the two Weihrauch guns (HW50 and HW35) which are 75 years old this year that are still in production and enjoy playing with them a little.


All the best Mick

[TonyL]

I'm always about, Tone.

Just having a bit of a nightmare balancing the drugs I'm on, and if I don't have anything worthwhile to post I keep quiet.

I'm still fascinated by the two Weihrauch guns (HW50 and HW35) which are 75 years old this year that are still in production and enjoy playing with them a little.


All the best Mick

Excellent stuff, Mick.

And.......isn't it just brilliant that these two classic guns can still kick the backsides of most modern springers out there?

[TonyL]

I had an enjoyable little session with it yesterday. The firing cycle is nice and quick but most certainly not harsh. I probably had about 60 or 70 shots. I'll let it run in for a little longer and then check the power again. If I deem the power then to be a little too close for comfort, a slight spring crop should make for an even sweeter firing cycle. We'll see how the old girl settles.

[T 20]

And.......isn't it just brilliant that these two classic guns can still kick the backsides of most modern springers out there?

Try as I might, I can't think of any gun, past or present, that comes anywhere near these two.

[Shed tuner]

Not so much an insight as an observation, Jon.

I've missed your observation then

Weirdly I can actually picture this now you mention it... I obviously thought about the weight, but never considered the extra spring room that it would create ! Doh....

[TonyL]

Try as I might, I can't think of any gun, past or present, that comes anywhere near these two.

Agreed. But I can't deny how much I love the '77, Mick. I don't think I'll ever forget how gobsmacked I was back in 1984 upon first trying my first one out. SO accurate and so easy to get to that accuracy.

[T 20]

Agreed. But I can't deny how much I love the '77, Mick. I don't think I'll ever forget how gobsmacked I was back in 1984 upon first trying my first one out. SO accurate and so easy to get to that accuracy.

Aye, Tone, but the 77 isn't an 11- 12ftlb break barrel gun.