[lostification]

Ok, I was just doing my regular cleaning and I thought I'd just see how well sealed my cylinder was. You guys know what I mean by compression test right? Pull the piston back and put your finger on the end of the cylinder head to prevent air from coming out. Turns out that I have no compession at all.... This can't be right....

 

[cellbuster]

Well it's entirely important, I was never able to completely stop it (especially with my 170), but increasing to a stable compression does help. The stock O ring is better then the NEO piston O ring.

 

[gestapo]

You have to push the piston IN, not out. I'm not sure about the VSR series rifle, but some have POM piston heads which only have compression when being pushed into the cylinder.

 

[elphantasamo]

Now this got me thinking.

Why not make a tool, similar to the compression tester used on internal combustion engines, to just such a test on airsoft guns?

 

[lostification]

Compression is only needed to maximize efficiency. Seen how I am above the fps limit already, it is unimportant. However, if you need more fps you may want to improve your compression for the best possible fps without having to buy a new spring that is harder to pull.

 

[cellbuster]

Well, whats the max FPS? I would suggest taking other smaller steps to increasing fps and then switching to a weaker spring, I've just always had that mindset.

 

[gestapo]

You will always want maximum compression possible. It creates the most constant velocity. Compression is the whole thing that makes airsoft guns work.

 

[Livonia]

There are some pistons made that if you have a jam or something it will stop the air from coming out, pretty neat actually. forgot who makes them.

Using teflon tape on all of your threads will prevent this even more, i have perfect compression on my 96, to the point where the escaping air pushes my finger away from the nossle after a second or two.

 

[cellbuster]

Thats pretty sweet. I was never really able to achieve perfect complression, mine always leaked some what.

 

[gestapo]

Alot of FPS is lost between the hopup and the nozzle. That's why stock TM M14's shoot as far as like... 350 FPS M4s. The amazing hopup.