Z-grip RT Classic - rebuilt!

[Cyco-Dude]

um...someone did tell you that that isn't the correct piston right? that's an old version piston for an automag classic valve. the piston you want is this.

come on guys; he has an rt classic. you all should've picked this up right off the bat.

[Pghp8ntballer]

I asked bout that twice. Outright saying it does not look like the one in the blow up diagrams.

[Cyco-Dude]

I asked bout that twice. Outright saying it does not look like the one in the blow up diagrams.

lol, they were too busy talking about the o-ring to notice it was the wrong part i guess!

[vintage]

i never opened the pics at work since so many people were helping.

[athomas]

I was so fixated on the oring, that I didn't even look at the piston assembly. Ha ha. That'll cause a problem for sure.

[Spider-TW]

I didn't think a non-RT piston would fit in there and work for any amount. I thought I just didn't remember what the classic RT piston looked like. It was weird, but I just didn't believe it. That's worse than my friend asking me to tune his minimag that was missing the whole on/off top assembly.

[Pghp8ntballer]

It happens. I was able to get the piston ordered with the other parts and not get double tapped on shipping so no harm done. Oddly enough, it seems to be the perfect size for the classic valve piston as well. Its not too tight and not too loose.

[ChristianFromPitt]

I'm always impressed at this community. It's like a bunch of mag detectives working together with a lot of expert eyes that can spot things I wouldn't notice.

[Pghp8ntballer]

I am a little late with the update. I got my parts in earlier this week and was able to rebuild it. All new orings throughout sans L10 and the new reg piston. I only had larger carriers for the L10 so the new L10 stem orings leaked with the ones I had. I ended up just replacing the carrier exterior boring and leaving the L10 as-is since it did not leak to begin with. It shoots and chrono's fine.

However... I am noticing bolt stick/reseting issues. I have tried cranking the thumbscrew down and various states of tightness. Snugged good with an allen wrench seems the most reliable. The issue is not always occurring but its like the air is choked off and there is a lack of a trigger. If I push the bolt back with a dowel, the trigger resets. Could the new orings in the on/off need broken in? Could the front screw need tweaked? I also thought I might be getting choked off at tank reg but I tried 2 different PE 3k tanks and my armageddon system. I did notice that it seemed vaguely more reliable at a higher output. *NOTE* I am outright against pumping high pressure into a marker. 900psi had it shooting decently. I tried up to 1100 but it did not make a difference... even in the RT department. I tried 3 different mainsprings too. The one that came with the gun, the new L7 RT spring that came with the new rebuild, and a red L10 spring. It felt like it was causing lighter or stiffer trigger pulls. Does that make sense? It did have a bit of an effect on the sound signature and feel of the marker as well as varying effects on the antichop (All of this testing was done dry firing). But I was still getting the issue with all the springs.

Onto the RT tuning. Since I took it up to 1100psi with no avail, I decided to file the pin down. The original length was .740" I did try the ULT shims. Any more than two and the on/off was too thick to sit flush and it didn't seem to have an effect. To the file I went. I filed about .005" to .007" or so off at a time and retested. I couldn't shoot much since the armageddon is set up on a 17ci 3k tank. At .724", I started to feel the RT coming about. It was feeling better, but still slow. My goal is about a 10-15 bps RT. I went a little further with the pin. I am down to .719" at 900 psi but I ran out of air on the little tank. I guess I will have to set the Armageddon up on a bigger tank since it seems to run the best at 900 psi So... to be continued.

Does any of this make sense to you?

[athomas]

However... I am noticing bolt stick/reseting issues. .... If I push the bolt back with a dowel, the trigger resets. Could the new orings in the on/off need broken in?

Gnerally, if the trigger resets when you push the bolt back, then the issue is powertube related. It is usually a bolt stick issue caused by a carrier oring that is too tight.

Check the body washer to see if the hole is mushroomed. A mushroomed hole could cause the bolt to rub, adding to the friction which would require more force to reset the bolt.

[Pghp8ntballer]

I will look into the body washer. But do the stainless bodies have the washers? I thought that was for the aluminum bodies?

Carrier oring... the white one that the bolt stem goes through or the black exterior carrier oring?

I work late this week so I may not get a chance to tinker with it until the weekend.

[Cyco-Dude]

I am a little late with the update. I got my parts in earlier this week and was able to rebuild it. All new orings throughout sans L10 and the new reg piston. I only had larger carriers for the L10 so the new L10 stem orings leaked with the ones I had. I ended up just replacing the carrier exterior boring and leaving the L10 as-is since it did not leak to begin with. It shoots and chrono's fine.

However... I am noticing bolt stick/reseting issues. I have tried cranking the thumbscrew down and various states of tightness. Snugged good with an allen wrench seems the most reliable. The issue is not always occurring but its like the air is choked off and there is a lack of a trigger. If I push the bolt back with a dowel, the trigger resets. Could the new orings in the on/off need broken in? Could the front screw need tweaked? I also thought I might be getting choked off at tank reg but I tried 2 different PE 3k tanks and my armageddon system. I did notice that it seemed vaguely more reliable at a higher output. *NOTE* I am outright against pumping high pressure into a marker. 900psi had it shooting decently. I tried up to 1100 but it did not make a difference... even in the RT department. I tried 3 different mainsprings too. The one that came with the gun, the new L7 RT spring that came with the new rebuild, and a red L10 spring. It felt like it was causing lighter or stiffer trigger pulls. Does that make sense? It did have a bit of an effect on the sound signature and feel of the marker as well as varying effects on the antichop (All of this testing was done dry firing). But I was still getting the issue with all the springs.

Onto the RT tuning. Since I took it up to 1100psi with no avail, I decided to file the pin down. The original length was .740" I did try the ULT shims. Any more than two and the on/off was too thick to sit flush and it didn't seem to have an effect. To the file I went. I filed about .005" to .007" or so off at a time and retested. I couldn't shoot much since the armageddon is set up on a 17ci 3k tank. At .724", I started to feel the RT coming about. It was feeling better, but still slow. My goal is about a 10-15 bps RT. I went a little further with the pin. I am down to .719" at 900 psi but I ran out of air on the little tank. I guess I will have to set the Armageddon up on a bigger tank since it seems to run the best at 900 psi So... to be continued.

Does any of this make sense to you?

the z-grip is not the best for rt'ing in my experience. the stock carbon grip or a modified intelliframe would be best. as for the pin, frankly i think that way beyond spec. you might try a .712 pin with a quad o-ring (that's what is used in an emag) and see if that helps. beyond that, i think either get a different frame or a different gun, or otherwise just use it as-is until the o-rings break in. i don't think continuing to alter the pin will be good in the long run, but it's your gun...

[athomas]

The body washer in the stainless bodies, is the washer that is welded in place between the valve and the breach area.

The carrier oring is the white one that you are adjusting with the carriers. The black ones on the outside of the carriers rarely need replacing and never cause issues unless you actually break them.

[Pghp8ntballer]

Got to try some troubleshooting this evening. I aired it up and set to 900psi as before. This is with the pin at .719". It cycled the same, but the brief RT effect seemed closer to what I wanted. The bolt stick still seems prevalent. Off the top of my head, the trigger rod gap was about the thickness of 3 credit cards. I shortened it to about a single credit card thickness. It seemed to cycle a lot better but still plagued by bolt stick. The RT effect felt spot on for the speed I want and lasted a bit longer. It's still tricky to get it to RT. Oddly enough, if I do not try to RT and just fan ( I think that is the right term for it) the crap out of it, it shoots good. Single or slower shots sometimes stick. Throughout this I did turn it down to 800psi and got essentially the same results except the RT was not as quick/easy to attain.

I took a peek down both ends of the body. I don't see any damage or mushrooming of any kind. I will have to try the next size up carrier.

My Armageddon tank valve also sprung a leak during troubleshooting

[athomas]

The RT effect depends on the sear cycling quickly. If you are getting bolt stick, it will affect the ability to RT. Get the bolt stick issue fixed, and your RT effect will probably be fine, or at least be much easier to adjust.