FWB mod 2

[deliterman]

This is a older Co2 but up untill now has been a real good shooter. a week ago i notice that some shots the pellet would drop. so i checked the velocity and noticed that it was very inconsistant it would drop as much as 50 fps and then the next one would be right on for 4-5 shots then back down.any thoughts on this?any info would be appreciated thank you.

[toznerd]

Unlike the later Feinwerkbau CO2 guns, the Model 2 taps the cylinder for each shot, with an intermediate pin. As opposed to the design used by later Feinwerkbau CO2 pistols that stage a specified volume of gas and a separate valve used to tap the staged gas. There can be several cause for inconsistency:

-Weak striker spring (easily replaced)
-Drag on the striker (clean and dry lube- do not use oil)
-drag on the intermediate striker pin in the receiver (clean)
-CO2 leakage at the cylinder seal located on the receiver or at the upper/lower receiver junction (small o-ring)
-worn/dirty cylinder valve seal inside the cylinder (clean/replace as needed)

There is a good chance it hasn't been rebuilt (at least not recently), so it is probably due. Although I'll add that 50 FPS out of 500 is not a huge variation, considering the distance. Not quite World Class consistency, but I had a Model 65 that varied about 35 FPS before I rebuilt it, and it still shot great. Obviously, the Model 2 is capable of standard deviations as low as of 5 to 10 FPS.

Good luck,

toznerd

[deliterman]

Thanks for your reply sounds like good info. what kind of dry lube are you talking about? looks like i will have to take it apart and give it a good cleaning and going over .again thanks for your help.

[toznerd]

Any decent spray on x-flon (te-flon, cer-flon, etc...) dry lube should work, as long as it is a very light coating. A thick coating tends to have the opposite effect on reducing friction. I have also used dry extra-fine grade molybdenum disulfide powder. With a soft patch, burnish the powder onto the part, and then lightly brush on a trace before installation. Be careful, as the powder has a way of imbeding in paint and leaving silvery-gray stains that are hard to remove.


Good Luck,

toznerd

[deliterman]

Thank you very much on your info, I did replaced the seal ,cleaned and re placed evry thing ans also reapplied to all moveing parts some very fine moly paste. it's black but like you said it will turn everything silvery. we will see if that works,BTW I didn't see anything out of the ordenary or broke.thank you again for your help.

[deliterman]

reajusted the velocity down to about 500 fps and it is much better but some times it does drop down some but not as bad as befor.what would be a normal standard deviation for this gun? that would be a good stating point at this time .any thoughts on this?again thanks.

[Muffo as guest]

If it helps I use to shoot a model 2 and I was having a similar problem but i couldnt get it to go out any faster that 500fps My mother has a model 2 that was originally a test model for feinwerk when they were first made. it goes out at about 540fps and hardly varies at all. it is also more accurate than my old model 2

[deliterman]

yes, the mod2 I have is very old but I can crank it up to 560fps but one out of 10 will drop down to say 480 fps. but works fairly well @ 500fps now, my friend has a FWB-C10 and it work very good @ 485fps.no up and no downs.anyway thanks for all the help! BTW I just noticed that the 1st stage travel is just about 1/16 " don't bother me but others that shoot with have much more travel is that short 1st stage a problem to be looked at ? or a'm I just nit picking? thank you.