Webley Mk3 (serial 9350) - Piston Washer Advice

[chieffool]

Getting hooked on this now!
I have some spare springs in the "extensive parts store"
Will do some measuring/ spring rate comparison & see what's going on. Keep breathing!!

Chores come first

Much appreciated if you can rummage around to check.

Haven't taken out the NEW (Titan) spring i got through Airgunspares yet, but measurements for the softer/Original Webley spring i removed are:

29 Coils:
225mm long (because old and knackered...?) IF it is supposed to have about 30/40mm preload - then should be 255/260mm ?
3.2mm coil width [varies between 3.17 up to 3.25+ in places....]
21.3mm outer diameter

NB: can't really get an 'inner' diameter off the vernier as the flattened end coils prevent but obviously clears the rear spring guide.

[deejayuu]

Gotcha! Chieftool

[flatrajectory]

It is well known that Titan springs are very stiff and not nice to shoot. It is also known that a longer softer spring is nicer than a shorter stiff one. ........no crude jokes please..!
Wonky donky has some springs made for modern rifles that are so soft you can cock them with 2 fingers yet they still make full power. As far as I know he doesn't make one specifically for your Webley, but one may fit.
If you email him with your dimensions he may have something.
Pete.

[chieffool]

Much appreciated if you can rummage around to check.

Haven't taken out the NEW (Titan) spring i got through Airgunspares yet, but measurements for the softer/Original Webley spring i removed are:

29 Coils:
225mm long (because old and knackered...?) IF it is supposed to have about 30/40mm preload - then should be 255/260mm ?
3.2mm coil width [varies between 3.17 up to 3.25+ in places....]
21.3mm outer diameter

NB: can't really get an 'inner' diameter off the vernier as the flattened end coils prevent but obviously clears the rear spring guide.

Just stripped out the new 'titan' spring. TWO things to note:

1. I was CONVINCED this spring was a lot longer. The Titan is actually 223mm
( vs the original Webley which is 219mm, and NOT 225mm as reported above)

2. Titan is definitely stiffer. This we know... just nice to know absolutely.
I could rig up some sort of jig to compare compression (perhaps based on level of depression under a fixed weight)....
...but why bother - They are NOT the same! (or even similar) in terms of performance.


SO - BEFORE I DO ANYTHING WITH ALTERNATE (OR SHORTENED SPRINGS)...
I'm going to try out the Protek 'softer' washer (due tomorrow?) to see which one works best with the existing/old softer spring.
ie hopefully identifying best seal, then i'll try out various spring solutions afterwards.

[Phil Russell]

For what it is worth, I have yet to fit a Titan spring that does not need shortening. I have fitted a few 'as is' and have often found power to be low despite a lot of effort in fitting the spring. Power also varied considerably between pellets but as I removed coils one by one the power increased and the differences in output between different pellets decreased. OK, at times power has been too high but this is clearly not relevant to you.
So my guess is that your rifle is oversprung even though spring length is the same. In simple terms, overspringing results in the air compressing too fast to allow it to exit the transfer port effectively; it creates a blockage which clears slowly, hence low power.
Re tap leaking: I test crudely for tap leakage by having the rifle loaded and then placing a moistened (oil is fine) bit of tissue over the tap loading hole in the cylinder. Fire the rifle ... a leaky tap sends the tissue heavenwards.
Cheers, Phil
PS: make sure your new leather washer is a smooth sliding fit in the cylinder. It is OK to have to push it down with light pressure but if you have to exert much pressure it is too tight. Also check that when fitted, there is no lost volume at the piston head due to a leather rim ... but bear in mind that the rim will settle backwards as the base of the washer settles into shape on the piston head ... with most washers, when first fitted, there is a space around the perimeter of the piston head where the leather washer joins it; this space disappears as the sides of the washer are forced back onto the piston head.

[thisisdonald]

For what it is worth, I have yet to fit a Titan spring that does not need shortening. I have fitted a few 'as is' and have often found power to be low despite a lot of effort in fitting the spring. Power also varied considerably between pellets but as I removed coils one by one the power increased and the differences in output between different pellets decreased. OK, at times power has been too high but this is clearly not relevant to you.
So my guess is that your rifle is oversprung even though spring length is the same. In simple terms, overspringing results in the air compressing too fast to allow it to exit the transfer port effectively; it creates a blockage which clears slowly, hence low power.
Re tap leaking: I test crudely for tap leakage by having the rifle loaded and then placing a moistened (oil is fine) bit of tissue over the tap loading hole in the cylinder. Fire the rifle ... a leaky tap sends the tissue heavenwards.
Cheers, Phil
PS: make sure your new leather washer is a smooth sliding fit in the cylinder. It is OK to have to push it down with light pressure but if you have to exert much pressure it is too tight. Also check that when fitted, there is no lost volume at the piston head due to a leather rim ... but bear in mind that the rim will settle backwards as the base of the washer settles into shape on the piston head ... with most washers, when first fitted, there is a space around the perimeter of the piston head where the leather washer joins it; this space disappears as the sides of the washer are forced back onto the piston head.

thanks for that Phil - that post contains a couple of those wee nuggets of detail that only comes with experience and saves the rest of us having to brainstorm! cheers.

[chieffool]

thanks for that Phil - that post contains a couple of those wee nuggets of detail that only comes with experience and saves the rest of us having to brainstorm! cheers.

I've stripped out the new Knibbs washer to resoak sunday, and refitted monday afternoon with the OLD webley spring. I know the old spring is knackered because when cocked without stock i can see the coils bunch and spread in uneven groups down the length visible through the slot. But better that than oversprung. The gun is reassembled with the spring 'at rest' for 24hrs (ANOTHER MEMBERS ADVICE) to make sure the resoaked washer forms to the shape of the air chamber. i'll test and re-chrono tues evening.

1. When the protek (softer washer) arrives i'll try that to compare...
2. and while hunting for a softer spring (original webley if it is out there) i'll try removing some coils off the titan with test results for each stage.

THATs the PLAN

[thisisdonald]

keep us updated Chiefy. Ive got an oversprung, near mint 60s mk3 here and this is all good heads up advice for me for when I get round to sorting.

[deejayuu]

Chieftool and all interested. Here's a bit of innards and friends/foes gathered yesterday?
The original measures 200 mm. The Webley tagged Mk lll AR40 measures 240 mm. Bought as "new old stock" but no guarantee of course.
Other dimensions match and all 29 coils.


The other two black springs bought as Mk lll are odds on non standard. Inside diameter is smaller so tight on guide.
The "Silver Streak Mk lll" measures 250 mm and all other dimensions match.


"nose to tail" load test shows original softest then S.S. and the two others stiffest.

Any/all observations welcome.

[deejayuu]

Here's the '59 spring 210 mm alongside the '65 200 mm.



Looking closely at the tagged spring which I bought as "Webley new old stock" it certainly looks the part.
Can anyone say with certainty what the original free length was/is?
Thanks for looking.

[chieffool]

Chieftool and all interested. Here's a bit of innards and friends/foes gathered yesterday?
The original measures 200 mm. The Webley tagged Mk lll AR40 measures 240 mm. Bought as "new old stock" but no guarantee of course.
Other dimensions match and all 29 coils.


The other two black springs bought as Mk lll are odds on non standard. Inside diameter is smaller so tight on guide.
The "Silver Streak Mk lll" measures 250 mm and all other dimensions match.


"nose to tail" load test shows original softest then S.S. and the two others stiffest.

Any/all observations welcome.

From my conversations with BOTH Protek and Knibbs the Knibbs (ie airgunspares) part no AR40 used to genuinely be Webley new/old stock.
If we believe the 'tag'.... then 240mm was the original length.

IF SO - why are both companies shifting a new/stiffer spring that is only 220mm?
ANYONE?

[chieffool]

re comments above:
so far I only seem to hear from people who don't like the new springs, and the comments i'm getting are 'softer' old-type springs are better.

CAN I ASK - IS THERE ANYONE OUT THERE WHO LIKES THE NEW/STIFFER SPRINGS?

[deejayuu]

Fitted one of the black stiffer springs 240 mm free coil bound 100 mm then 230 mm relaxed.
Very high effort to fit and cock. I'm no judge but seems harsh firing and only gets 450 ft/s

Tried the "webley tagged" slightly softer. Lengths as above.Still hard work & harsh to me but gets 490 ft/s.

Next took the black one down to 220 mm. Easier to fit obviously. Still hard cocking and firing but makes 540 ft/s
This about spec. for the rifle methinks.

More tampering to follow.

[chieffool]

Fitted one of the black stiffer springs 240 mm free coil bound 100 mm then 230 mm relaxed.
Very high effort to fit and cock. I'm no judge but seems harsh firing and only gets 450 ft/s

Tried the "webley tagged" slightly softer. Lengths as above.Still hard work & harsh to me but gets 490 ft/s.

Next took the black one down to 220 mm. Easier to fit obviously. Still hard cocking and firing but makes 540 ft/s
This about spec. for the rifle methinks.

More tampering to follow.

can't thank you enough for taking the time to try that all out.
I've got more feedback/info to report out:

• .... having tried BOTH the Knibbs (part AR20) 'hard' washer that you have to shape/soak/etc VERSUS the Protek supplied 'softer' washer (which comes with absolutely NO instructions, but which i was briefed on over the phone on how to fit. This does NOT shape/fit in the same way).

• .... comparison figures on reducing Titan-like spring now available (same source) from both protek and knibbs

• .... possible source of new/softer springs for older guns???

The delay is from time required to 'bed in' leather washers to get 'like-for-like' comparison figures.
Report to follow later in week

[chieffool]

I've got a parallel thread running on the 'general topic of springs for older guns at:
http://www.airgunbbs.com/showthread....re-MAINSPRINGS

MEANWHILE:
Have 'redone' my new Knibbs 'AR20' hard leather washer. If you glance back on this thread you'll find suggestions on 'compression' test cocking/decocking with the tap open and closed.... shall we call it the 'HISS' test?

My new shaped AR20 washer was lasting about 4 secs under compression.
SO: (don't laugh) i stripped it out, separated the inner flat leather washer from the outer cup and soaked both for another 12 hrs (olive oil).

I figured the 'cup' is shaped, but the inner washer could be adjusted to squish the cup out further.

So: removed the inner washer and dried it. Placed on flat metal surface (i have some old steel printed blank dies that make great little anvils) and gently hammered at the edges with a hammer to 'widen' the washer.
NEXT: reassembled and screwed the washer set back into the top of the piston.
NOW: the washer spreads out wider than the piston head (when i took it out to soak it was very 'flat' and parrallel to the piston)

GETTING IT BACK IN: tough. had to carefully 'scoop' it into the start of the air chamber (as more spread out now)very carefully with the tip of a wide flat screwdriver (VERY GENTLY) and then 'wind' the washer in along the threads - just like winding the trigger block in. Once passed the threads, the washer was smooth, but i kept gently turning as i pushed it down inside the air chamber to stop the slot the cocking arm slides along 'shaping' the soft edge of the washer. CAREFULLY i also gently got the edge of the washer to slide past (edge of a smaller screwdriver this time) the end of the slot until finally inside the proper air chamber. And then gently slid home ensuring everything lined up properly.

Reassembled.
Left everything 24 hrs (too much?!) overnight to settle to allow the washer to 'fit itself' into the chamber.

WOW: Compression test NOW 14 secs (instead of 4) and very sweet.

Just need a f@kkin spring that works now!!