Long stroking a HW99 and HW35 ?

[T 20]

I was just wondering if anyone had tried this ?

I only ask as I've found a readily available seal which would increase the HW99's stroke by 5mm if the piston seal arbor was machined to suit.



All the best Mick

[robs5230]

I was just wondering if anyone had tried this ?

I only ask as I've found a readily available seal which would increase the HW99's stroke by 5mm if the piston seal arbor was machined to suit.



All the best Mick

Whats the thinking behind considering long stroking the 99 Mick?
Cheers

[evert]

I was just wondering if anyone had tried this ?

I only ask as I've found a readily available seal which would increase the HW99's stroke by 5mm if the piston seal arbor was machined to suit.



All the best Mick

Is it the Cometa seal?
The 99 with a some mm's extra stroke is actually a really good idea.

[les allam]

The Webley Longbow as been long stroked ,possibly for shot feel in .177 cal.
The 99’s can be a bit lively over 11 ish fp in .177 as well.
I would guess the 99’s had a longer stroke than the L/b as standard.
They are both nicer in .22 imo.
Les..

[NickG]

I had a go at a 99 a few years back, I made a lightweight o ring piston at the same stroke.It was faster , but I couldn't honestly say it was improved, so I didn't bother with it .

[T 20]

Whats the thinking behind considering long stroking the 99 Mick?
Cheers

Hi Rob

I've never owned a 99, but I've read a few posts where folks have said that the .22" HW99 easily runs nicely at 11+ ftlbs but the .177" HW99 only runs nicely at 10+ ftlbs.
So my thinking on long stroking the 99 is mainly to get a bit more swept volume for the .177" guns to try to gain a little more power.

The other thing I've read regarding the HW99 is that there can be a variance in cylinder sizes where an oversize OD seal could be a benefit.

As I long stroked my Oldschool HW50 by fitting a TX seal, when I came across this seal I realised the same stroke gain could be had by using it on a HW99.

Is it the Cometa seal?
The 99 with a some mm's extra stroke is actually a really good idea.

No Evert, I was looking at this one, but I am looking at all the seals available for another project :-


image.jpg


It's cheaper than the Weihrauch seal as well --- win, win.





All the best Mick

[evert]

Good to know, might get one on my next oreder.
The chinese tubes for the B26 are reputed to be variable in size, so an oversize seal for the chinese guns makes sense.
There are several other diana/AA style seals out there that are larger than 25mm.
Theres the OEM Cometa 26mm seal, ARH/Maccari makes oversize seals for varying tubes plus a Cometa 26mm seal,
and the Australian guy also makes a Cometa seal supposedly at 26,6mm. So plenty to choose from!

[TonyL]

Never tried it. My answers would align with yours and those of Les re the Longbow, Mick, so guessing it could well bear fruit, especially for .177s (although, personally, I've never felt there was an issue). The 95's stroke is, I think, 14mm longer than the 99's, and many do report pleasing results from short stroking them a little, so if the extra 5mm on a 99 gets it into the same territory?

Can only concurr with the price observation, too.

[robs5230]

Hi Rob

I've never owned a 99, but I've read a few posts where folks have said that the .22" HW99 easily runs nicely at 11+ ftlbs but the .177" HW99 only runs nicely at 10+ ftlbs.
So my thinking on long stroking the 99 is mainly to get a bit more swept volume for the .177" guns to try to gain a little more power.

The other thing I've read regarding the HW99 is that there can be a variance in cylinder sizes where an oversize OD seal could be a benefit.

As I long stroked my Oldschool HW50 by fitting a TX seal, when I came across this seal I realised the same stroke gain could be had by using it on a HW99.




All the best Mick

Mmmm...
A well setup 99 in .177 running at 10.5-11 can be pretty amazing Mick.
Anyone saying they aren't nice over 10 needs to tune differently or use another tuner.

I'd agree with a possible variance in cylinder size though. I've done 2 recently.
1 an early 99 and a brand new one.
The cylinder is definitely tighter in the newer one. What difference this actually makes, I'm not sure, until I can get both back here to compare them.
What I will say, is that they're both among the nicest springers that I've ever shot. Very smooth and mild mannered.

Very interested to see how you get on with this.

[T 20]

Mmmm...
A well setup 99 in .177 running at 10.5-11 can be pretty amazing Mick.
Anyone saying they aren't nice over 10 needs to tune differently or use another tuner.

I'd agree with a possible variance in cylinder size though. I've done 2 recently.
1 an early 99 and a brand new one.
The cylinder is definitely tighter in the newer one. What difference this actually makes, I'm not sure, until I can get both back here to compare them.
What I will say, is that they're both among the nicest springers that I've ever shot. Very smooth and mild mannered.

Very interested to see how you get on with this.

Oh, I won't be doing anything with a HW99, Rob.

I only buy Weihrauchs with screw in trigger blocks and no silly writing on them.


I just put this idea out there to see if anyone had tried long stroking one a tad ?






All the best Mick

[TonyL]

Ah, but one day, Uncle Mick, a 99 will come along and cast its alluring spell on you and you'll be smitten. Never say never, and all that.

[robthedog]

Not having much knowledge on this subject, so please bear with me, but long stroking would increase the volume of the cylinder so more air ?, just thinking it would make it better suited to .25 cal or am i totally wrong ?

Rob

[maximus]

I guess you could always get one of those ready long stroked 99's, more commonly known as a 95😁

[oldskoolzzz]

I was just wondering if anyone had tried this ?

I only ask as I've found a readily available seal which would increase the HW99's stroke by 5mm if the piston seal arbor was machined to suit.



All the best Mick

I’ve done completely the opposite Mick

What I call a shorter, short stroke experiment when I was dabbling with a reduced power 99 for 10m opens thrills.

Actually worked really nice got a local engineer mate of mine to band the piston as well for me so had a nice glided short stroke setup using one of Tinners short stroke kits.

I was always under the impression in simple terms the 99 is a short stroke 95 therefore what I did was to make a short stroke an even shorter stroke

I’d never considered doing the opposite though and making the 99 more 95 esq in its stroke as that’s food for thought although I’ve never really gelled with the 95 as I preferred it when I short stroked that one as well.

Not much help I’m afraid

[coburn]

The 57 has stroke between the 95 & 99. It might be worth aiming for that?