[Newballer]

Im new to this forum and to paintball, i read your rules page but i couldnt quite figure out where to put this so since im new, i guess this is a good place, plz dont delete it and ban me if it isn't, just let me know and i will remember next time.

To the topic though, i recently bought a PMI Piranha and was having a couple of dificultys with it. The first turned out to be a broken O-ring in the gun but i got that fixed but i have a question. My friends have O-rings on their barrels but mine didnt when i got it. It was used so i was just woundering if i should slip an O-Ring on there or if it didnt matter. The other thing is a little weird and none of my friends can figure it out. My gun loses compression every time i fire and pumps the bolt back a couple times like when its empty and then just stays in the uncocked position and then when i try to fire again, it just rolls outta the barrel and hits the ground. I notice it also blew an O-Ring off my tank and when i put a new one on it and let a friend use it his gun blew it off again. The threads where you screw it in look a little messed to me, i could take a picture and post it if you like. It may just be the tank but i think its the gun as well. I checked the O-Rings inside again and they are fine. Any suggestions?

[Nor*Tex]

Ok ill try and get all this in, if i miss anything or you have ne more qs pm me


1. you dont nessacrily need a barrel oring, it just helps reduce the wobble and provide a tighter seal
2.Check your tank, you might be running low, if thats not it, and all the o-rings have been checked, oil your gun up and try again.
3. It is possible the tank threads might be a bit messed up, if so c02 tanks are cheap, just get another, Also as for the oring problem, yall mite just be taking the tank off improperly.

Again, welcome to the forum, if you have any more qs pm me or catch me on aim(txlx77)

[doublethreatguy]

welcome to the forums.
you posted correctly .

I would put an o-ring on your barrel. it allows for a tighter fit.

As for your bolt problem, i have no idea.

Threads on co2 tank: if you think they are messed up, you could get a new tank. If it can screw into a gun, i would think that they are fine.

[Kleivonen]

if it wasnt your fault you might be able to get your tank exchanged if you got it at a proshop. if not id just buy another tank if possible

welcome to pbf

[counterstrike53]

You dont need an Oring on your barrel, so you dont have to worry about that.

Originally Posted by Newballer

The other thing is a little weird and none of my friends can figure it out. My gun loses compression every time i fire and pumps the bolt back a couple times like when its empty and then just stays in the uncocked position and then when i try to fire again, it just rolls outta the barrel and hits the ground.

Do you mean when your tank is empty, the gun kinda goes into "full auto" for a second? If it does, you dont need to worry about it, thats the normal thing for the piranah to do when the tank is empty. The reason the ball just rolls out of the barrel is because there is no air left in the tank to propel the ball further than that, the only thing pushing the ball is the force of the spring on the bolt which in turn will push the ball out of the barrel.

[Newballer]

I'll try one of my friends tanks then and see what happens. I know about the empty thing though, i actually got to play one full game before all this started happening. The tank was full, had it filled 1hr before i went down. The reason i said the threads look messed is that they sorta look serated at the bottom, its hard to tell cause i can't look at them dead on but it seems as though the end of the last thread on the bottom is bent down. I'll try the tank and get back to you, thx for your suggestions.

[Dogpatch]

This would actually go in the Stacked Tube Blowbacks section, there is a PMI sub forum there. But it's all good.
The o-ring on the barrel isn't absolutely necessary, but it doesn't hurt either. The barrel can come loose and the o-ring will help keep it tight.
As for the gun not recocking, I recently had this problem as well. Make sure there is nothing in the air line. You can remove the ASA and grip and just blow air through them. I did this and found junk in the line, blocking air flow. I went ahead and changed my hammer spring, valve pin and cup seal also. Newer Piranha's have the valve pin and cup seal as one piece, so... I suggest you check the air line, lube it up good and try it. After that it might be time to start looking at parts.
Welcome to the forum!

[Mescaline]

a friends of mine implulse was doing the same thing and was having huge psi spikes. took it too a pro shop and it turned out to be the o-rings around the solenoid.

[spyderkid101]

My spyder did that once with the bolt thing, just oil the bolt and it should be fine. Also, my friend's tippman did that bolt thing once too, he would shoot and it would make the noise like he was out of CO2, then he would cock it and it would keep doing that even if he had a full tank. Your gun might just be starved of oil. Just put a couple drops o your bolt o-rings and you should be good. It might not be the solution, but it worked for my friend and I.