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FAS 6004 .3mm disc for piston

Posted: Mon Mar 01, 2021 1:52 pm
by ArTee
I have a 6004 and 2 pistons. One stock and one I would like to add a .3mm alu disc in order to bring the pressure up. I was considering using either LOKTITE 262 Red or JB WELD 8272 to bond. HOWEVER does anyone have and willing to sell a .3mm disc that I can do that and any possible suggestions, comments or experiences?

Thanks in advance.

BTW I like the way the gun fits in the hand. I have RINK grip that I only slightly filed down the ridges for the fingers since they cut into my hand. I also soot a IZH 46M which is nice and all that BUT (and remember the word "but" negates all that came before) the simply 6004 feels good. I have a DOCTER sight on top of the base that's sold by the guy in NH. It works fine and is quite robust contrary to those who mentioned the possible strength or lack thereof of the device as attached. There is no issue. It works!

Thanks again in advance for any assistance.

Rick Tornello

Re: FAS 6004 .3mm disc for piston

Posted: Mon Mar 01, 2021 10:05 pm
by spektr
Just thinking our loud....
If you decrease the volume of air being compressed and use the same spring to provide the force, it's not clear to me that pressure or velocity would go up. The pellet is moving before the piston completes its stroke. Im not sure that the pressure curve of the smaller volume being compressed geta you what you are looking for.........

Re: FAS 6004 .3mm disc for piston

Posted: Mon Mar 01, 2021 10:21 pm
by brent375hh
spektr wrote: Mon Mar 01, 2021 10:05 pm Just thinking our loud....
If you decrease the volume of air being compressed and use the same spring to provide the force, it's not clear to me that pressure or velocity would go up. The pellet is moving before the piston completes its stroke. Im not sure that the pressure curve of the smaller volume being compressed geta you what you are looking for.........
I thought the 6004 was a ssp.

Re: FAS 6004 .3mm disc for piston

Posted: Mon Mar 01, 2021 11:20 pm
by spektr
I thought it was a springer, my bad.......

Ill go back and pretend im Rover......

Re: FAS 6004 .3mm disc for piston

Posted: Tue Mar 02, 2021 11:30 am
by ArTee
The 6004 is an SSP.

If you look on the extended FAS 6004 string you'll see what I'm talking about. I was hoping someone would have access to thin ALU discs. I've done all the other things suggested and they work. The gun shoots ally pellets without an issue too.

Thanks,

rt

Re: FAS 6004 .3mm disc for piston

Posted: Wed Mar 03, 2021 11:33 am
by clarky
You can use 0.5mm PTFE tape with peel off and fix backing. There is 0.7 mm dead space in the 3 6004s i have done, so the O.5mm is a safe bet without dead heading and straining the pivot pin.....De-grease, or even rough up the front of the piston face first with a bit of course abrasive .

...but before you do this, you need to make sure the breech is sealing correctly, or it will leak more due to the higher compressed pressure. Its a careful balancing act.

Finally, everyone is getting it wrong with pellets for this gun....its because its a match pistol that Wadcutters are being automatically chosen. It works so much better with 8 grain domes such as AA, or JSB RS. They have faster start rates.

Re: FAS 6004 .3mm disc for piston

Posted: Wed Mar 03, 2021 1:34 pm
by ArTee
Clarky, a very sincere thank you very much. I will run a sealing test as per the 6004 string and then get some tape, then test it again. I was wondering about that when i read on another site that someone else was using it. I am also curious how it would hold up to the pressure and the bit of oil that was necessary every now and then for the o-ring and the felt wiper.

The people at Chiappa here in the States have been very nice and I don't have any negative issues.

RT

Re: FAS 6004 .3mm disc for piston

Posted: Tue Mar 09, 2021 1:45 pm
by clarky
You are right to be suspicious of lubes working their way under the plastic and loosening it off. It happens...often a few 1000 shots to do so, but easy enough to replace if it does.
For me, i machined up a disk in alloy and spot faced it into the piston head, gluing in with Red Loctite, but i understand not everyone can do the machine work, so i suggested a quick fix. ..You could try some 0.5mm shim and glue on with a proprietary engineering glue....

Re: FAS 6004 .3mm disc for piston

Posted: Wed Mar 10, 2021 8:11 pm
by ArTee
I made the tape addition, cut the 3mm slit as per your suggestion and I'm at 410/414 fps. Not bad. The pumping pressure is not an issue.

Re your disc, that's why I was looking to see if anyone had a 3MM piece of metal that I could spot face it as you mentioned. I used to make model ships and hand made and or fit small metal pieces by hand. I would do the same here too though the manufacturer mentioned that the tape and adhesive were supposed to be resistant to oils and other chemicals. I'll keep track of the pellet usage and failures.

The biggest pain was and has always been getting the felt wiper stuffed into the cylinder!

I don't understand what Chiappa doesn't sell an upgrade with the increased thickness or that 3mm to 5 mm slight increase in piston length thereby eliminating all this bother.

Thanks again,

RT

Re: FAS 6004 .3mm disc for piston

Posted: Thu Mar 25, 2021 3:01 pm
by ArTee
This is 10 shots, H&N Alloy @ 10 meters with all the mods you and the others have offered up. BTW having cataracts and such the dot (Docter Sight that's been upgraded for heavy use) is fuzzy/flares so I'm not to upset. In the past wit better eyesight the grouping would have been tighter. I also used AIR RIFLE targets to help get the zero quicker. The dot just about covered the black but again with the eye issue I was never "sure" what was really centered. The balance is great just under the trigger guard a bit forward. The FPS is 411 +/- a few fps. I added a Rink grip. The gun feels good and in an odd way reminds me of my old Pardini SP22, balance feel and just does.

Chiappa was great in getting me the spares so I could make the mods without destroying the OEM parts.

Thanks for the help.

Rick Tornello