HW50 the original version. Spring option

[Mach 1.5]

Yes Tony. My venom 55 runs at 10.5 ft lbs. I purchased Steve a 55T a few years ago as it was his favourite HW but sadly he never got round to finishing it off. Yes Mick my current 55 T as the aluminium piston in it. Mach 1.5

[T 20]

Mine just says "HW55 M".

I've just dug mine out and it just has HW55 then the f in pentogram stamping.

I suppose I ought to pull this one apart before machining, as I might need to make two pistons --- I've already bought two TX seals and four HW80 breech shims, just in case.

[deejayuu]

The HW55MF was a complete HW50 action dropped into a target stocK, Paul.

There is a question mark over the HW55 pistons though as I've read that some are different to a HW50 piston, being made of steel and aluminium.

Here's some pistons https://photos.app.goo.gl/oV326shX1yjiirW88
May be able to try a Titan 7 for size tomorrow

[T 20]

Here's some pistons https://photos.app.goo.gl/oV326shX1yjiirW88
May be able to try a Titan 7 for size tomorrow

So far I've only played with synthetic sealed HW50s, but from your photos I can see straight away that the leather sealed pistons have less spring room in them.
The end plug in the piston on the synthetic sealed pistons doesn't extend as far backwards as your leather sealed ones, this follows what I described the other day on HW35s.



All the best Mick

[TonyL]

Reading this again it read like a right load of old bollocks, so I've slapped her back together again (twice) and run her over the chrono.

After washing the cylinder out, the first time I put her back together with Walther piston lube, with this the piston seal felt tight so I stripped her and washed her out again.
Then I burnished some dry slide in the cylinder walls and changed the piston lube to the molly that I normally use and away she went 590fps with .22" superdomes 650fps with Hobby.

I've lost 20fps just by stripping the gun and putting her back together, but I expect her to bed back in after some use.

The bit that made me wonder was the 200mm long spring, it didn't sound feasible, but looking at the spring data thread I noticed that the TX MK2 only used a 200mm long spring.

So all good again.

Excellent!!

[TonyL]

Here's some pistons https://photos.app.goo.gl/oV326shX1yjiirW88
May be able to try a Titan 7 for size tomorrow

Excellent; thank you. Be interesting to hear your updates.

[TonyL]

Yes Tony. My venom 55 runs at 10.5 ft lbs. I purchased Steve a 55T a few years ago as it was his favourite HW but sadly he never got round to finishing it off. Yes Mick my current 55 T as the aluminium piston in it. Mach 1.5

Cheers for that, Paul. Such a shame that he never got round to finishing it.

[TonyL]

I've just dug mine out and it just has HW55 then the f in pentogram stamping.

I suppose I ought to pull this one apart before machining, as I might need to make two pistons --- I've already bought two TX seals and four HW80 breech shims, just in case.

So far I've only played with synthetic sealed HW50s, but from your photos I can see straight away that the leather sealed pistons have less spring room in them.
The end plug in the piston on the synthetic sealed pistons doesn't extend as far backwards as your leather sealed ones, this follows what I described the other day on HW35s.

All the best Mick

The T20 mojo is definitely back!

[T 20]

Here's some pistons https://photos.app.goo.gl/oV326shX1yjiirW88
May be able to try a Titan 7 for size tomorrow

Hi Jules.

I forgot to say --- could you measure the spring please, as there seems to be a discrepancy in its wire size on the Titan chart ?

No big problem if you can't --- the manager of Knibbs is a member on here so I could ask him for dims ?



All the best Mick

[deejayuu]

Hi Jules.

I forgot to say --- could you measure the spring please, as there seems to be a discrepancy in its wire size on the Titan chart ?

No big problem if you can't --- the manager of Knibbs is a member on here so I could ask him for dims ?

All the best Mick

Titan 7 fits the 50 piston with enough slack for, probably, a 0.5 mm sleeve
Measured in hand at 255L x 19.8 OD x 3.02 wire x 3l/29 coils x 42 lb.f/inch
My slight concern is the rate being too high as found. May scrag down a bit which could help.
Will try to fit it to one of ours and feed back.

[TonyL]

Thank you for that, sir.
Not far off the measurements quoted then, but off anyway. I wonder if those quoted measurements are "simply wrong" or if this is down to inconsistencies / manufacturer sometimes switching wire diameter subject to availability issues?

[T 20]

Titan 7 fits the 50 piston with enough slack for, probably, a 0.5 mm sleeve
Measured in hand at 255L x 19.8 OD x 3.02 wire x 3l/29 coils x 42 lb.f/inch
My slight concern is the rate being too high as found. May scrag down a bit which could help.
Will try to fit it to one of ours and feed back.

Cheers, Jules.

That is pretty well a match with the spring I have on my bench which I'm currently machining a HW50 piston body for based on its OD.
I can now reduce the piston ID based on your dimensions leaving a thicker wall at the base of the rear bearing and the reduced section between head and tail.

At 255mm long you'll have about 75mm of preload which is way over the top so I expect you'll be taking 4 or 5 coils off, maybe more.
on a search last night I found out that the genuine Weihrauch HW99 spring was 205mm long which is the nearest equivalent we have to the oldschool HW50.
205mm closely matches the 200mm spring I'm using with 6mm of preload washers.

The spring ID also looks good giving you a 1.7mm wall on the spring guide ---- I actually found a Weihrauch nylon guide the right size to fit mine, I just need to take 1mm off the base washer OD to fit the cylinder.


Thanks again




All the best Mick

[T 20]

Thank you for that, sir.
Not far off the measurements quoted then, but off anyway. I wonder if those quoted measurements are "simply wrong" or if this is down to inconsistencies / manufacturer sometimes switching wire diameter subject to availability issues?

Jules' real world measurements are a mile away from those quoted on Bagnal and Kirkwood's site, Tone.


Miles away when machining that is.

[T 20]

Oh bugger --- based on Evert's measurements I'm now getting the urge to drive to Knibbs to purchase a Titan Number 7.

[evert]

Oh bugger --- based on Evert's measurements I'm now getting the urge to drive to Knibbs to purchase a Titan Number 7.

HUH? Me?