Stroke lengths, TP sizes and SCR for various springers...

[brucegill]

you can tune springers to shoot heavy pellets more efficiently, this is done with stroke and transfer port, shorter stroke and so smaller TP to give a higher peak pressure and would you believe a springer starts acting like a PCP.

when i did that 25mm 80 you shot at the bash Bruce originally it was favouring 16 to 20gr pellets more than 15 and under, Hobby were under 9fpe but baracuda hunters were 13+fpe, it took me a while to get my head round it but i eventually worked on the stoke and dialled in Hobby shooting at the same power (near enough) and get this the high and low met in the middle...the 19gr come down to 11+ and the 12gr went up to 11+

This notion springers shoot lighter pellets more efficiently is due to poor design, not what springers can do. Im thinking an LGV in .22 with a DE spec piston will be quite the machine for this, if anything it may just need a few mm of stroke adding to equal things up at worse.

Some more great info! Many thanks Tony.

I have to to say, I did bloody love that .22 80!

[bigtoe01]

Some more great info! Many thanks Tony.

I have to to say, I did bloody love that .22 80!

well you can make your own when you get a nice lathe to do the bits on...there are a few places that carry the 30/25mm tube.

Or...why not try a HW95 with 23mm sleeve, so 85mm stroke 23mm piston have the cocking shoe push back on the piston skirt like on the LGV and make the piston rotate.

85mm stroke is 35CC or 80mm is 33CC (approx) plenty enough for 11fpe and the action has decent spring room

[T 20]

By Bosch!! Oh my, I really cannot believe that!

At least I've had a little tonic for the day....that got me laughing!

Boys, you've got nowt to worry about!

Hi Tone


I didn't know if you'd realised but the video is of this bloke:-

http://www.airgunbbs.com/showthread....02#post6225002




All the best Mick

[brucegill]

well you can make your own when you get a nice lathe to do the bits on...there are a few places that carry the 30/25mm tube.

Or...why not try a HW95 with 23mm sleeve, so 85mm stroke 23mm piston have the cocking shoe push back on the piston skirt like on the LGV and make the piston rotate.

85mm stroke is 35CC or 80mm is 33CC (approx) plenty enough for 11fpe and the action has decent spring room

Thanks mate. Hopefully have another nice stock coming for an 80, so it will be on the cards!

I vaguely remember seeing you saying 25mm isn't the most efficient size. Not worked out how you've worked that out yet but now I'm starting to understand the SCR side of things, I'll do some calculations and see why. Well, hopefully lol.

[brucegill]

Fair point but if custom builds are added you will need this info. Also, as in the TX, different weighted pistons by use of different top hats dictate calibre size in std form. Don't know how much detail you want but suspect more rather than less��
Anyway, here's some data on a TXHC

Stroke - ~98mm
TP - ~3.65mm x 9.8mm long
Piston wt - ~225g (.177 add 27g for top hat)
(.22 add 16g for top hat)
Bore dia - 25mm

Hiya

Can you just confirm if thats a MK3 and standard? Have added details above

Many thanks!

[TonyL]

Hi Tone


I didn't know if you'd realised but the video is of this bloke:-

http://www.airgunbbs.com/showthread....02#post6225002

All the best Mick

Hi Mick,

Cheers for that, yes, I had realised it.

Quite scary, eh?

[brucegill]

Hi Bruce, its probably worth adding a swept volume column to save calculator punching

The SCR is difficult as the target value depends on port length as the gas flow through the port is restricted more by a longer port, it's an indicator of when it will slam or bounce.

Cheers

John

Hi John

Sorry, I missed your post.... Have added Swept Vol. Will add TP Vol. shortly. After that, I won't be adding any more columns as its a PITA in HTML.

Can I get some TX info off you?? Looks like we have MK3 details. Would be great to have MK1/2 and a check on the above figures mate!

ATVB
Bruce

[T 20]

This may help a bit Bruce

http://i675.photobucket.com/albums/v...ingerchart.gif





All the best Mick

[brucegill]

This may help a bit Bruce

http://i675.photobucket.com/albums/v...ingerchart.gif





All the best Mick

Many thanks mate! I'd seen that a while back but couldn't find it.... I'm going to be doing this for bloody ages lol. Executive decision: Not including Gamo lol

[TonyL]

Executive decision: Not including Gamo lol

How about these rifles, also, Bruce? :-

The HW99...that's a must.

Webley Longbow, Patriot and Tomahawk.

RWS / Diana 52, 280, 34

BSA Lightning derivatives.

Classics :-

HW50 and 55.

Webley Vulcan, Omega and Eclipse.

Those lovely little BSFs.

BSA Airsporter and Mercury.

You're right, I can see you being busy!

[T 20]

How about these rifles, also, Bruce? :-

Vulcan

Vulcan --------- Cylinder 27mm X 79mm - transfer port 2.5mm X 19mm

Webley Hawk --- Cylinder 25mm X 79mm - transfer port 4mm X 16mm

Westlake B2 ---- Cylinder 25.4mm X 80mm - transfer port 4mm X 28mm




All the best Mick





PS:- notice how I managed to slip a B2 in there Tone --- Bruce may never notice if we keep quiet

[TonyL]

Westlake B2 ---- Cylinder 25.4mm X 80mm - transfer port 4mm X 28mm

PS:- notice how I managed to slip a B2 in there Tone --- Bruce may never notice if we keep quiet

Was going to mention the little B2, but I just knew you'd slip it in there, all oily, like!

Going to collect Mercury S later (as long as it's okay). If he didn't have anything, all this talk of yours of the B2 was making me more than a little interested in one as a short range ratter....Those dimensions are way more than adequate, no? You could even lose loads of swept volume and have a really handy, sweet little, reduced stroke 9 foot pounder for Roland and his mates!

[brucegill]

How about these rifles, also, Bruce? :-

The HW99...that's a must.

Webley Longbow, Patriot and Tomahawk.

RWS / Diana 52, 280, 34

BSA Lightning derivatives.

Classics :-

HW50 and 55.

Webley Vulcan, Omega and Eclipse.

Those lovely little BSFs.

BSA Airsporter and Mercury.

You're right, I can see you being busy!

Absolutely! The more the merrier.

I only have an 80, 95 and 77 here now..... Might go and get a 99 soon though lol.

[brucegill]

Vulcan --------- Cylinder 27mm X 79mm - transfer port 2.5mm X 19mm

Webley Hawk --- Cylinder 25mm X 79mm - transfer port 4mm X 16mm

Westlake B2 ---- Cylinder 25.4mm X 80mm - transfer port 4mm X 28mm




All the best Mick





PS:- notice how I managed to slip a B2 in there Tone --- Bruce may never notice if we keep quiet

LOL, thanks mate!
Cheers

B

[tokoloshe]

Hiya

Can you just confirm if thats a MK3 and standard? Have added details above

Many thanks!

Yes, Mk3 Std. The Prosport is basically same spec if you want to add this too. Not sure about the very early ones though.