Just posted this answer in general airgun posts but believe it should be in Collectable & Target as a topic on it's own? If you don't agree let me know & I'll delete it from here!


All the FWB 600 series guns are 6ftlb ish.

The 600 introduced in the early 80s was the first FWB single stroke pneumatic & sported a laminate stock as standard; which I am led to believe; is called delignite? Walnut was an option but seemed to have been kept a secret over here for some reason!

The 601 was introduced & had a ratchet incorporated into the cocking lever.
there were two reasons for this, some shooters were very careless & let the 600 lever slip when under compression & knocked themselves out . & to eliminated the breaking of cocking linkage's so common on the 600.
The model was revised making the sight rail longer & FWB also played aroung with the piston seal, using a green coloured "L" shaped type "o" ring seal for a short period, but reverted back to the original design later.

The 602 was introduced with a slightly different trigger & stock design & was fixed with screws from the side above the trigger guard & one in the front of the stock verticaly in line with & parrallel the barrel as opposed to under the stock in a more "conventional" fashion. The front fixing caused the stock to split.
The sights were redesigned, the rearsight was two tone & enclosed giving a much more rectangular look & the 22mm front forsight was introduced.
A short tome after it's introduction a compensator could be fitted as a FWB aftermarket part.
The butt plate extension adjustment was revised & the was now capable of being twisted & slanted verticaly & diagonaly.
The 602 was discontinued after a very short production run.

The 603 was introduced with a compensater fitted as standard, the two rear side fixing stock screws remained but the front screw was placed under the stock, although I believe some versions had two front side fixings,for some reason, like the wooden stocked P70, the two tone sights went to all black.

There are other difference's & slight variations within models.