[JustASimpleSniper]

Piston weight may or may not increase fps. It may induce joule creep increasing FPS, but at the same time may slow it enough to reduce FPS. Besides that, maybe a thick foam dampener on your cylinder head, the little bit of lost volume may drop it.

 

[1tonne]

Wrap solder around the piston and hold it on with electrical tape.

 

[TinCan]

Wrap solder around the piston and hold it on with electrical tape.

I wish I had a soldering iron to do this, maybe the foam dampener will work. I am guessing I can chrono with the hop on? Because thats the fps I would be playing with anyways, usually I chrono with it off

 

[Reliku]

You can just use cold soldering wire, just the plain wire. Get the leaded stuff, it's better for soldering should you ever need it and it's also heavier so better for joule creep.

The rules may state you need to chrono with hop off. Keep in mind the fps will be higher with hopup on, especially with heavyweights.

 

[TinCan]

Sigh, after spending the morning trying to get great air seal and I failed

I put 8mm heat shrink on cylinder head, and did dental floss and PTFE to bucking but it the piston still goes forward instantly

 

[1tonne]

Make sure you have Teflon tape around the thread on the air nozzle as the air may be escaping through there.

 

[SilverLion]

Have you tried putting Teflon tape under the piston o ring, or have you tried heat stretching the o ring?

 

[Wiltsu-boy]

Sigh, after spending the morning trying to get great air seal and I failed

I put 8mm heat shrink on cylinder head, and did dental floss and PTFE to bucking but it the piston still goes forward instantly

I would say start with the easiest which is the cylinder compression. What parts do you have installed?t When you get 100% seal in your cylinder, then try the hop up. If you dont have already, just get the action army hop up unit, it seals very well. In case you are going really on a budget, you could do antiblowby rings from brass tubing/similar. Thats gonna seal your hop up. Not sure about the diameter, probably its like 9mm, but dont make it too tight

Oh wait, in your earlier comment, you asked for advice how to reduce fps...? Sooo whats your goal

 

[TinCan]

I am currently on 499.4fps which is my goal. That was before the heat shrink cylinder head mod. I guess I will chronod with a tiny bit of hop as that's what I will play with. I have mainly done diy mods as far. I have an original tm bucking in it. I ament entirely sure how air seal works in the cylinder. I just put Telefon tape around the thread. But could it be something to do with the stock piston?