fwb 124 query

[hamiclar01]

Hi all,

I finally plucked up enough courage (and tools) to take my battered 124 apart.

I followed the online guides available, and the gun is now reduced to greasy bits on the workbench.

Problem: the piston took a lot of huffing and puffing to get out of the compression chamber. I had assumed after the cocking link came out, the piston would just slide out. Was I being presumptuous? Or is there a catch ?

My worry is , if it took that effort to come out, how will it go back in?

Thanks in advance

[Garvin]

Once the little shoe that the cocking link fits into is removed by gently working it out of the widened part of the cocking slot, the piston should come out easily. If it doesn't then you may need to reduce the diameter of the piston seal until the piston falls gently down the cylinder under its own weight. In the past Jim Maccari has mentioned some "tight tubed" FWB Sports being built - maybe you have one of these?

[hamiclar01]

Thanks!

[red bob]

getting the spring compressed back into the action was i found the most testing,i was lucky in having a new workshop with everything to hand ,in this case a long heavy duty reckord sash clamp blocks and vice.slowly pushing the spring back in while sweating that nothing slipped,fwb springs must be one of the longest even my orig45 didnt seem quite so long .shes back to her full potential and has regained her place as my hunting rifle of choice.still havent sorted the barrel droop yet which makes scope zero a pain.if you have trouible in reassembly there are at least 4 mems on here who can assist and have some great tricks to help sort various probs.

[I. J.]

If the piston head has deteriorated with age it may have broke up and a part may be jamming the piston in the cylinder.
A cheap alternative to an original piston head or Maccari one is a BSA Supersport which requires a bit of reduction in diameter.

ATB
Ian

[T 20]

On the last sport I played with the piston seal was a nice fit, although the front face was convex, closing the transfer port before the piston came to rest.

I just put the piston in the lathe and machined the front face of the seal flat (it was a quick rebuild), just doing this raised the power quite a bit.


All the best Mick

[Morningstar]

I have found my sports run very well using the standard HW77-97 springs in them about 29 coils with a tophat fitted. They are a much tighter fit on the guide and a lot less effort to fit too. they are running very consistent as well as quieter. I also size the piston seal on a lathe too and fit a piston sleive out out poycarbonate pop bottle, which quietens things a bit more.
I must admit I am tempted to machine the spring guide off and recess the trigger block and fit a rotating delrin guide to see if this makes things even smother? Your opinions would be most welcome on that idea?
Well thats my two penny worth.
ATB Graham

[johnj]

I found on one of my Webleys that the piston was very tight to remove from the compression tube.

However it was rarely used for ten years and the tightness was due to dirt, rust and grime build up on the walls of the compression tube.

Once cleaned and polished the seal was actually a perfect fit so before altering your seal clean everything up and try putting it back together to see.

Ofcourse if the gun is as old and battered as you say you could treat it to a new seal

Johnj.

[TopDog]

Hi

Great tips from the previous members and the first thing to do is thoroughly clean all the dismantled parts for inspection (makes them easier to handle too!).

Having a natural dread of compressed items springing free and causing extensive damage to me, someone else or even the gun prompted me to post this pic of a spring compressor I recently made to replace one which went "walk-about" during our last house move. I have overhauled a BSA Lightning XL and FWB 124 recently with it and with absolute safety and ease.

I can produce a dimensioned drawing if required but it's just as easy to put the things where you may need them (I like to make things as universal as I can but there will always be the odd-ball which catches one out). A hardwood rig does permit rapid re-arrangement of course!

The only critical thing is to make certain that the centrelines of all items, compressor screw, cylinder locator, barrel locator line up well. Mine is 60mm above the 90mm wide baseboard to accommodate the screw handle swing!

This may start (or continue) a trend!!



ATB
David

[hamiclar01]

Thanks for the tips gents.

The gun was sold to me as having an ox spring. When I opened it up it did have preload, and I thanked the compressor I'd built for myself!

I suspect the tight fit is either grime, or the piston head. Of course, a tight piston as Garvin says is an option too. But I think , as Johnj says, I'll give everything a good clean and see how things go.

I have a Maccari old school kit that I hope to install. The spring is short, so I have a feeling it might be installable without a compressor. Best to keep it around though!