HW50 the original version. Spring option

[TonyL]

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


Miles away when machining that is.

Yep, appreciated, Mick.

[TonyL]

HUH? Me?

Don't panic, evert. Mick meant Jules.

[T 20]

HUH? Me?

My bad --- sorry.

[Mach 1.5]

No.7 Fits:
BSA Polaris, Webley Tracker, Osprey, Excel, Viscount, Xocet, Stingray, Falcon, Hawk MK1-3, Norica, Relum (using existing inner), Baikal, Cometa 5, Haenel Mod. 303, Gamo Sniper, Commando, Delta, Expo, Apache, CF16, Rangemaster, Statical, Magnum, Gunmark Phantom, NAC, HW30, HW50 HW55 & HW55T, Gamo 1000, Shadow, CSI, Whisper, Gamo 68, Norica 73,

Was it 24 coils for the HW50..Mick. Mach 1.5

[deejayuu]

Cheers, Jules.


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.
All the best Mick

My concern is that shortening by that amount would stiffen to the point of 'oversprung'

[T 20]

No.7 Fits:
BSA Polaris, Webley Tracker, Osprey, Excel, Viscount, Xocet, Stingray, Falcon, Hawk MK1-3, Norica, Relum (using existing inner), Baikal, Cometa 5, Haenel Mod. 303, Gamo Sniper, Commando, Delta, Expo, Apache, CF16, Rangemaster, Statical, Magnum, Gunmark Phantom, NAC, HW30, HW50 HW55 & HW55T, Gamo 1000, Shadow, CSI, Whisper, Gamo 68, Norica 73,

Was it 24 coils for the HW50..Mick. Mach 1.5

Hi Paul.

Don't forget that these measurements come from a standard synthetic HW50 piston that's longstroke by 5mm by simply fitting a TX200 piston seal.

I'm running 24 spring coils including the closed ends giving 23 air gaps between coils, there is 6mm of preload washers in the gun including top hat weight --- I could have probably used another coil or two and left the 4mm of rear preload out.

Piston weight is 198gm including the piston weight.

With a standard stroke gun (65mm) I'd be inclined to start at 26/27 coils, then test and chop accordingly.



There is a thread in the collectors section from 12 years ago by flatrajectory on the HW50, where Bigtoe recommends a 210mm long spring for a simular set up as mine, and I'd say he was spot on.

Overall spring room in a cocked HW50 is 112mm so you shouldn't go coil bound.



All the best Mick

[T 20]

My concern is that shortening by that amount would stiffen to the point of 'oversprung'

I don't do all that working out spring rates, Jules.

I just stuff a spring in that I think is near enough, chrono and then chop until I get the firing cycle I'm after --- if I chop a bit too much I fit preload washers.

With HW35S and HW50S I don't even put the built action back in the stock to chrono, I just chrono the action as is.
I also don't nip up the back blocks to chrono, I chrono with them slightly loose so that if I have to remove the spring I simply cock the top sear and remove the back block with the Rekord unit still in it.

Once I'm happy with the firing cycle I lube the spring and slam the whole gun back together --- job done.

[T 20]

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.

I don't know why I did a search on the HW99 spring as I realised last night that I have a pile of them in my used spring drawer.

Used/scragged they measure 220mm long 21mm OD with 3mm wire, 25 steel coils including the end coils, 24 air gaps.

Though these won't fit the oldschool HW50 they give a pretty good indication of where to go with a 20mm OD spring.

[TonyL]

I don't do all that working out spring rates, Jules.

I just stuff a spring in that I think is near enough, chrono and then chop until I get the firing cycle I'm after --- if I chop a bit too much I fit preload washers.

With HW35S and HW50S I don't even put the built action back in the stock to chrono, I just chrono the action as is.
I also don't nip up the back blocks to chrono, I chrono with them slightly loose so that if I have to remove the spring I simply cock the top sear and remove the back block with the Rekord unit still in it.

Once I'm happy with the firing cycle I lube the spring and slam the whole gun back together --- job done.

Loving your more casual way of approaching spring rate etc., Mick. That's just how I'll be approaching shortening the spring on that naughty '35 of mine. Nice enough already but if I can get it sweeter still, that'll be a bonus. And I want that put to bed and completed so that I can make a start on my own old-school '50.

[deejayuu]

I don't do all that working out spring rates, Jules. :

Nor me. I use a bathroom scale on a drill press table with a guide rod in the chuck. Sad I know but lets me choose spring start point quicker.
That's my story anyway

[TonyL]

That's more than most of us would do, sir, and a nice, ingenious way of measuring the spring rate to remove some of the guesswork.

[TonyL]

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

Did you get one, Mick?

[T 20]

Did you get one, Mick?

Based on the measurements I realised I already had one on my bench, Tone.

It's already chopped to about the same length as a factory 99 spring, so that will do for now.
I've also found a standard Weihrauch spring guide that fits a 19mm x 3mm spring which opens up my choice of springs as I have a few 19mm OD springs.

Depending on how the b2 piston works out in this action I may not need the 20mm spring.

[TonyL]

Synthetic HW guide or the older, steel one, Mick?

[T 20]

Synthetic HW guide or the older, steel one, Mick?

Synthetic, Tone.

UKNeil gave me all the old springs and guides he'd removed from guns in order to fit VMach kits in them when he retired as a VMach fitter.