Fwb124 piston seal replacement

Here are some links I found when I tried to do mine this year. I had problems getting the spring out using wood clamps so I decided it would be better to let somebody with the experience and correct tools do it instead. I put a Maccari kit into it and its great.

https://www.airrifleheadquarters.com/page/page/251483.htm

https://www.rimfirecentral.com/forums/showthread.php?t=292368

http://anotherairgunblog.blogspot.com/search/label/Feinwerkbau

http://anotherairgunblog.blogspot.com/2009/10/derricks-two-tone-fwb-124.html

https://forum.vintageairgunsgallery.com/feinwerkbau-rifles/feinwerkbau-modell-124/

You will need a spring compressor. Use a small block of wood against the end but not interfering with the safety. Back it out slowly and use zip ties as it comes out and they will hold the safety in place. When replacing, leave them on and cut the first one when the front of the safety is well inside the tube. The last one can just be pushed off. Hope this makes sense.

Should also mention, when starting use very slight pressure on the end cap to facilitate removal of the bolt that holds the end cap in place. When replacing the bolt, it is critical that the bolt hole in the tube and the screw hole in the cap line up perfectly. It is very easy to cross thread it! You should be able to finger thread it all the way in. If it is tight and you are using a wrench on it ..it is probably cross threaded.

On 124/127 guns, the ROOF of compression chamber can and will get the old seal material pounded into the corners.

You need to fabricate a long scraper to get it all out of the corners against roof or the new seal will get screwed up as it impacts/ bottoms out against it.



A THIN WALL piece of @ 1/4"- 1/2" tubing crushed flat on the end, then ground flat to have sharp edges works great for this task.



Scott S