by Tom Gaylord
Writing as B.B. Pelletier

Part 1

FWB 300 disassembly instructions: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Today’s report describes how to disassembly a Feinwerkbau 300 air rifle. It was written for us by reader CptKlotz, our interpid German airgunner. We are breaking it into 2 parts because of the large number of photos.

If you’d like to write a guest post for this blog, please email me.

Over to you, CptKlotz.

This report covers:

Our thanks

Today’s report is the continuation and completion of how to disassembly a Feinwerkbau 300 air rifle. It was written for us by reader CptKlotz. Once again, do not attempt this unless you are sure you understand the instructions and can perform all of them safely!

If you’d like to write a guest post for this blog, please email me.

Over to you, CptKlotz.

This report covers:

  • Step 7.
  • Step 8.
  • Step 9.
  • Step 10.
  • Step 11.

This article was originally published on the German co2air forums ( It was created by the users Pellet (original text guide), Paramags (additional information and FWB150 details ) and boerni (photos and forum post). They kindly gave me permission to translate their guide so people who can’t read German can use it as well. The original forum post can be found here.

Translation by Stephan Szlosze (CptKlotz). Any text in italics is a comment from the translator.

Disclaimer: If you decide to work on your gun, you do so at your own risk. Neither Pyramyd Air,, the authors or I will accept any responsibility for injury or damage to you, your rifle or your equipment. Please read the guide carefully and proceed with caution.


I will pick up where I left off yesterday.

Step 7.


Now the trigger/ratchet unit must be removed. Loosen the screws shown in the picture. The larger screw (the one in the back) can be VERY tight. Make sure you use a screwdriver that fits it well and apply enough downward pressure so you don’t damage the screw’s head.

FWB 300 trigger ratchet
Loosen the trigger ratchet screws (arrow).

This picture shows how the unit is mounted.

FWB 300 trigger ratchet removed
Trigger ratchet mechanism has been removed.


Step 8.


Now, the cocking lever can be removed. It is held in place by a bolt that has a threaded upper end. It can be removed like a screw. The lever should be opened (same motion as cocking the rifle) so there is no pressure on the bolt.

FWB 300 lever bolt
Open the cocking lever and remove the bolt at the back of the lever.

Now the lever can be unhooked and removed.

FWB 300 lever unhooked
The cocking lever has been unhooked and removed.

Step 9.


The leaf spring sitting in a notch at the rear end needs to be removed. To do so, you need to remove another e clip (circlip) locking washer, and then remove the pin from the inside.

FWB 300 leaf spring washer
Remove the circlip and pull the pin to the inside.

When the pin is out, the leaf spring can be taken out. Notice that the angled tab at the end of the spring is pointing outward. Make sure to reattach it like this when you reassemble the rifle!

FWB 300 remove leaf spring
Remove the leaf spring from the inside. Note that the angled tab (on the right) is pointing to the outside of the tube.

Now, the last pin (which secures the springs) can be removed. It MUST be reinserted from the outside to prevent parts from being shot out of the action during the next step.

FWB 300 insert safety pin
Inserting the safety pin from the outside of the tube.

Step 10.


Now we will remove the springs and piston from the action. You need to loosen the large screw with the 17mm wrench (don’t remove it!).

Make sure the safety pin from Step 9 is still in place or the spring and other parts will be shot out of the action with great force!

FWB 300 loosen action screw

Step 11.


Now we actually let the piston slide out of the action. There are two ways this can be done:

1. By using a mainspring compressor

2. By pressing the action on against a non-slippery surface (muzzle up)

Now the action screw from step 10 can be removed completely. If you reduce the pressure a little, the spring will now press against the safety pin. You can now remove the pin and slowly reduce the pressure to slowly let the spring (etc.) slide out of the action.

I did it by myself by pressing the action against a shoe as shown in the picture. I am a fairly heavy male and didn’t have much trouble. The FWB300 is a 7.5 joule gun and thus has a weaker spring than the magnum rifles, but if the insides start flying out of the rifle, they will leave a dent in something. So be careful and if in doubt, ask a second person to help.)

FWB 300 compress spring
The action rests on my foot under pressure when I remove the safety pin. Hold onto the gun or parts will fly!

FWB 300 remove spring
Slowly relax the tension on the spring and the parts will fall out of the action.

Two pieces of metal that hold the leaf spring will also fall out of the action. They need to be reattached the correct way when reassembling the action.

When those two pieces came out of my rifle, I couldn’t see where exactly they had been sitting before. Getting them back in the correct way involved some trial and error, but it was obvious when they were back in place the right way. If you can, make a note of where those two pieces of metal sit before you disassemble the power plant.

This picture shows the parts of the powerplant:

FWB 300 powerplant parts
And there are the powerplant parts.

Put the rifle back together by reinstalling the parts in the order you removed them.

That’s it for the FWB 300. In the next report we will look at the differences of an FWB 150 and what special things we need to know to disassemble one of them.