[scoobabob94]

Ok, so I upgraded my sig 552 with the following compression parts:
-System reinforced piston
-Systema reinforced piston head
-Guarder steel cylinder head
-Guarder air nozzle for sig series
-KM TN inner barrel

For a spring I am using a PDI 170% and for the first few days after I upgraded my gun it was shooting at the propper fps which was about 410. Recently it started shooting much lower, at about 300 fps, so I took the gun apart and started checking out my airseal. I'm pretty sure that I am loosing a lot of air between my cylinder head and my nozzle. I tried first putting my finger over the cylinder head and pushing the piston in and it was pretty much a perfect seal, but then when I tried to perform the same test with the air nozzle installed I could see that a lot of the air was leaking out around the base of the air nozzle. I tried lubing the air nozzle where the air was escaping but that didn't really help. I also tried it was the stock TM air nozzle and I was still losing a lot of air in pretty much the same area. So I guess what I am wondering is will I have to buy a new air nozzle or is there some way that I can stop the air from leaking out around the base? Also is there any other spots that I should be checking for leaking air such as around the hopup unit? If so how do I do that?

Well I'm stumped, any help would be much appreciated