TargetTalk

Shooting my new FWB '80 on sunday and while its accurate enough, the sound on firing is a definite "Twaank"
I used to shoot an FWB '65 and Im pretty certain it didnt sound anything like that...

Anyone have any ideas please?

It still ís a spring pistol. Maybe a broken mainspring.
Did you chrono it?
It can vary per weapon too, allthough you wouldnt expect this much variation between pistols in case of a brand like FWB.
Allthough, my FWB300 twanged too. The Diana 75 did not.

Doesn't sound good.

Send it to Pilk. If it ain't broke he won't charge much. If it is broke, eat it.

My FWB 80 still has the old springs, but new seals and the sound on firing is a “twang”. Your gun has new or old seals, springs, and does the slide normally return to battery when you tilt the pistol downward or when cocking the lever?

As long as the gun is grouping fine and you haven’t noticed any vertical dispersion at ten meters, don't worry.

Ar-15 rifles tend to go "boinng" from the recoil spring. Because it's in the buttstock, it's very close to the ear & easy to hear. The traditional solution is to put a fair amount of grease on the spring. This helps to damp down the vibrations quickly.

I have no idea if this would help, but it might.

Not chrono'ed it yet, but as I said ist grouping fine, triggers bang on and cocking etc is as you would expect.

FWB recommend NOT greasing the spring, probably to prevent dieselling, so Im wary of doing that, besides Ive never stripped an FWB yet so no idea how tricky it will be.

On a sporting air rifle I would have sleeved the piston and fitted a guide tube that was turned to the optimum dimensions at the drop of a hat, just wary of toying with something like the FWB. On the other hand I know things do move on and there may be room for some improvements using modern materials and parts.

BTW Im in the UK so suggestions on parts and tuning may be academic, unless a UK shooter knows different?

Bill

billy.noon wrote: BTW Im in the UK

Can I suggest adding your location to your profile.

billy.noon wrote:FWB recommend NOT greasing the spring, probably to prevent dieselling, so Im wary of doing that, besides Ive never stripped an FWB yet so no idea how tricky it will be.

No need to grease the springs, just a small dab of moly on the piston ring groove. If you've never stripped the 65, then the pistol probably has the old seals.

I suspect they've deteriorated and the piston head is slamming against the front of the compression chamber without any air cushioning. Mark Cones from the UK, did a detailed strip on the 65:

http://www.airgunbbs.com/showthread.php ... u-Model-65

http://www.airgunbbs.com/showthread.php ... ost4545004

If it's spring vibration, look up "Heavy Tar" and it will help with vibration. It will not diesel and combust.

CRC engine assembly grease with molly is what I've used in the past for rebuilding spring guns and have had very good success. If your FWB uses leather seals (I have no idea how FWB 80's are made) 3n1 oil has been recommended by big-shots in the air rifle world. I used it in a vintage EIC brand spring rifle with leather seals and it smoked a bit, but nothing serious and it stopped after a few shots.