Hi, I just picked up a Winchester 363 (Diana Model 6) this morning at a gun show and of corse it will not shoot. I would like to tackle it my self as it is not in the best condition and not worth spending big bucks on. Are they too complicated for a guy with two left thumbs?
The Diana 6 uses the Giss system just like the match rifles did, I have a couple of these type of guns but have not tried working on them yet but have read about them. You will have to figure out a tool to unscrew the end cap on the receiver and also to remove the gear shaft plates. The original factory tool from what I have seen was a pin spanner and more than likely had hardened steel pins that were spaced correctly to fit in the holes in both the end cap and the gear shaft caps. There is also a tool needed to put pressure on the rear piston to take the load off the gears so that you can attempt to unscrew the plates. Basically getting seals may be your biggest problem as Umarex does not want to sell parts to rebuild the older Giss system guns. JM had the seals for the pistols a while back but haven't seen them on his site lately, he does have them for the rifles right now however. There is a article over on the American Vintage airgun forum on rebuilding the pistols which would be a good start, that forum is another network 54 forum and you should be able to find it with a google search. The one critical thing I know of to working on these guns is to check where the rear piston is before taking the gear plates and gears out, that is measure the distance from the end of the piston to the end of the receiver and when you go back together if you push the rear piston in to where it was you should be very close to getting the gears and caps back in. They are not the easiest guns to work on and untill I do one of mine I can't say how much trouble a person could run into, Umarex wants a nice price to rebuild these guns I do know that, if you need help finding the forum why just let me know.
Looks like it may be a little to hard for me to try. I have done a little research and I don't think I have the skills. I have rebuilt several springers but the giss I will leave alone. I may just list it on gunbroker as a pistol that needs rebuilt and see what happens.