Feinwerkbau 603.

[zooma]

I have finally got my 603 home - and what a beauty she is.

As I took it from its cardboard sleeve and out of the foam packaging, I found it hard to believe that it had even shot the claimed 100 pellets - it really is "as new" and I am delighted with it - a worthy replacment for my 601 ( a rifle I sold in a weak moment and regretted it ever since).

However, this rifle has a feature I did not have on my 601, and although it is not shown or mentioned in the owners handbook, it does look like it is an original part and not an aftermarket accessory.

On the left hand side of the loading flap there is a long tube that points backwards. As the flap opens this tube moves backwards, and when pushed forwards again it closes the flap - but not completely as it still needs pushing downwards from above to latch it closed as pushing this tube cannot do this.

I cannot see the point of having this partial closing option - so does anyone know why it is fitted and what it's advantage could be?

[Powderfinger]

I think it is a recoil absorbing device. It contains a small piston that absorbs the minimal recoil from a PCP or SSP. The same device is still fitted to current PCP FWB rifles. The FWB company website contains exploded diagrams of all FWB rifles and you can see the design of this tube and the piston inside it. To close the gun, push the flap down rather than pushing the tube. I am sure that someone who is very educated on the technical side of 10-metre shooting will be along soon to explain how the absorber works.

[zooma]

Oh - thanks for the explaination - maybe that also explains the black plastic circlip that can be slid along it - presumably to adjust the recoil in some way?

It seems strange to have this feature - but not to include it in the rifle drawing inside the handbook cover, or to explain its function. In fact there is no mention of it at all!

Do all 603 rifles have this, or was it something added to the later production - maybe this would explain why the handbook does not mention it as the handbook would not have been updated if the rifle was at the end of its production time?

If anyone has an answer for this the rifle number 317907 may help identify the production date. The dioptre is marked 4/04 but I can see nothing that looks like a date stamp on the rifle itself.

[Garvin]

Oh - thanks for the explaination - maybe that also explains the black plastic circlip that can be slid along it - presumably to adjust the recoil in some way?

It seems strange to have this feature - but not to include it in the rifle drawing inside the handbook cover, or to explain its function. In fact there is no mention of it at all!

Do all 603 rifles have this, or was it something added to the later production - maybe this would explain why the handbook does not mention it as the handbook would not have been updated if the rifle was at the end of its production time?

If anyone has an answer for this the rifle number 317907 may help identify the production date. The dioptre is marked 4/04 but I can see nothing that looks like a date stamp on the rifle itself.

Powderfinger is spot on, Bob. The anti-recoil device was the key development that distinguishes the standard 603 from the 602 (along with an improved stock mounting bolts arrangement, butt hook and updated sights). I have seen them retrofitted to earlier models, though I don't know how well, or how effectively. Occasionally you also see a 603 with the recoil absorber absent. I'm not sure why the handbook doesn't mention it. Probably because it doesn't require any operation as such.

[wonky donky]

The tube is indeed an absorber. It contains a piston, a floating tapered pin, a spring, a plastic cup & a screw.

It is held in place with 2 x 2.5mm screws, between which is a small o ring under the aluminium body.

The plastic circlip referred too covers a hole in the absorber body through which adjustments are made.

Adjustments can only be made when the absorber is in it's most rearward position & is by means of a screw.

The system works by bleeding a small amount of air from the transfer port upon firing & is only effective if correctly set up.

Yours is the later absorber as the earlier model did not have external means of adjustment.

Do they work.....well yes, but you have to be good to notice the difference as you will get more vibration from the tension being released off the cocking lever upon firing.

Oh yes, the piston travel should be between 12 to 17mm. If you do decide to alter it I suggest you download a FWB 700 manual where you will find instructions how to do it.

Hope this helps.....Enjoy

[zooma]

[QUOTE=wonky donky;5599660]The tube is indeed an absorber. It contains a piston, a floating tapered pin, a spring, a plastic cup & a screw.

It is held in place with 2 x 2.5mm screws, between which is a small o ring under the aluminium body.

The plastic circlip referred too covers a hole in the absorber body through which adjustments are made.

Adjustments can only be made when the absorber is in it's most rearward position & is by means of a screw.

The system works by bleeding a small amount of air from the transfer port upon firing & is only effective if correctly set up.

Yours is the later absorber as the earlier model did not have external means of adjustment.

Do they work.....well yes, but you have to be good to notice the difference as you will get more vibration from the tension being released off the cocking lever upon firing.




Thank you very much for the above information - it certainly answers all my questions.

I am still surprised that there is no real explaination or even a mention of it in the 603 owners handbook, and it is not shown on the drawings inside the front cover either.

I am guessing Feinwerkbau must have been satisfied with this "piggy-back" absorber if they have continued with it on their 700 series of rifles.

Do you happen to know if it is also continued on the new 800 by any chance?

Feinwerkbau only ever seem to picture their rifles from the right hand side, and so we never get to see the left hand side where this absorber is located.

Oh yes, the piston travel should be between 12 to 17mm. If you do decide to alter it I suggest you download a FWB 700 manual where you will find instructions how to do it.