[dansmith65]

So, I just got a used G5 today and it had a minor leak down the barrel. I replaced the two bolt orings and the gray back cap oring and the leak persists, although it's not as bad. I'm using TechT Gun Sav for lube. These are the only things I can think to do next...

• let it sit for a few days, then try again
• air it up and let it sit
• use dow 55 to swell the orings a bit

Do any of these make sense? Did I miss something?

FYI: There is almost no resistance when putting the back cap in the bolt - it slides on and off as though it's hardly touching.

[CA_Tectonics]

Does it fire?
Are you at proper operating pressure?

[Ahura_Mazda]

Hmm it's interesting that the back cap area inserts into the bolt with no resistance. I bought my G5 brand new and there's definitely a little initial resistance, so that o-ring may not be sealing very well. I say Dow 55 it and see what happens.

[dansmith65]

Yes it fires and chrono's very consistent. I fired a 14 round burst with average of 279 fps, low of 274 and high of 285. I don't have a pmd, so I can't verify operating pressure, but it's given me no reason to assume the pressure is off.

I just put some dow 55 on it; I'll see how it is tomorrow.

[dansmith65]

I played with the new G5 today and didn't have any leaks. Yesterday I wiped most of the dow 55 off and put GunSav on. It had really bad FSDO for the first few games, but I wiped the back cap oring and put a bit more GunSav on and didn't have that issue again.
There is still almost no resistance between the bolt and the back cap, but it seems to be working. I'll probably order some new orings for that in case this happens again.