Pick your poison and try to shoot it

[James_Blond]

So this is a gonna be a bit of a project. Hopefully I have all the parts and can get it working. Even got an old service request from the old field.

[James_Blond]

It’s functional so far… I had to take the set screw for the front rail screw and temporarily use it as the velocity screw/ front hammer spring screw as the few grub screws I had are too short. This is only a temp fix as it is still to short but long enough to test. Aired it up on a CA-II lever stock and it dry fires reliably. Can hear a slight hiss from the valve area. Not sure if its the two urethane orings around the valve body or if it’s internal to the valve.

Found a couple random buna. orings for the CA adapter for now. Need to shorten the screws I have for the hammer and bolt rail as they are slightly too long. Also there is a bit of a gap between the body and rail so the screws that were in the box might not be the original ones for it. So they might need to be cut down slightly to fully snug the body and rail up, unless this is the way the gun is?

So gonna need a trip to ace for some screws, possibly orings if they have what I need, and to polish up all the internals to get rid of the heavy oxidation. However, it does look like I might get this functional this week.

sure does have some kick. Kinda like a vm68 but somehow slower?

[JeepDVLZ45]

These are near markers. Looking forward to you getting this “full bore”!

[James_Blond]

Okay, little update now that the p68-AT is fixed and waiting on the some parts.

So on reassembly I noticed something strange. Almost every screw on this gun is 10-32. Set screws, grip frame screws. The rear linkage arm screw to the hammer is 10-32, however I noticed that the bolt to linkage arm screw is fitting kinda loose. Looking more closely I thought maybe the peaks of the threads on the bolt may be worn down, and this may be true, but the linkage arm hole to the bolt is slightly bigger than the hole to the hammer. I need to go check my shed for a 12-24 but the bolt threads look fine and the 10-32 does thread in pretty well. So I’m almost thinking it might be a 12-32? This size appears to be quite rare after a quick google search and might be hard to source. I wonder if it could be a metric size that got used for some reason?

So the gun remain down at the moment to I can either find the right screw or if it is getting worn out, I’ll have to either tap for a size up or helicoil the bolt body, but there isn’t much meat to the side wall of the bolt as it is riding on a powertube.

[James_Blond]

So a metric m5 fits a bit better than a 10-32. Might be a little bit sloppier than will hold up for a ton of cycling, but gonna have to go with it for now. M6 is way too big. Looks like long term, i may have to helicoil the bolt, though there is only about 1/8 worth of material to do it with and then grind down the helicoil. Or I may have to end up sending the bolt out to Doc or somebody to make a new one.

[James_Blond]

So I couldn’t find an m5 long enough to work. I’ve got some 10-32 helicoils on the way, which should arrive Monday or Tuesday. If that doesn’t work I’ll have to try something more substantial.

Also I cut the frame to body screw way down so there is no longer any visible gap between when tightened down.

[James_Blond]

So it isn’t perfect, but is functional and is a tight fit after installing the helicoil. Gun is cycling but shooting low at 160-180 on 12g. It likes to chop everything with my rotor but shoots fine hand loading. Velocity screw is backed all the way out so I think I need a bulk co2 tank and it may be getting too much friction and slowing the hammer down as well. Might be able to swap the valve spring for something lighter.

Shooting vid coming later once it uploads to YouTube.

[James_Blond]

Shooting vid from yesterday when it was warm out. It’s a bit rambing, but proof it is cycling even if it is shooting low.

https://youtu.be/alqrgAYuKeg?si=3WSkh9JxrP3AtW1Y

[William the Third]

You'll probably need a siphon tank if you want to get anywhere near velocity.

[wthomas333]

I have 2 Poisons that have both been rebuilt and cycle fine. But one does not get up to velocity while the other can shoot at good velocities even on hpa.
Not sure what the difference is between them that causes them to shoot so different.
Few years ago, I had Palmers make me a .685 brass barrel and that definitely helps. I could have gotten a .680 one too and should have in hindsight.

[James_Blond]

I have 2 Poisons that have both been rebuilt and cycle fine. But one does not get up to velocity while the other can shoot at good velocities even on hpa.
Not sure what the difference is between them that causes them to shoot so different.
Few years ago, I had Palmers make me a .685 brass barrel and that definitely helps. I could have gotten a .680 one too and should have in hindsight.

Strange having that kinda difference between them. I wonder if its possible to install the valve in such a way that the ports don’t line up or something so air flow is choked off? I’d need to pull the valve to see if there is anything like that which could be an issue. Really need a bulk tank though before doing spring and valve adjustments. Really want to get this up and running and take it to the field in the spring. Looks like a blaster from the space age tv shows. Wonder if I’ll get anyone who knows what it is.

A new barrel would help, but the paint I had wasn’t rolling out the barrel as its been open for a while and swelled a bit. So probably the barrel wasn’t that much of a factor.

Liquid co2 might just be the answer to this. Probably going to need to get my own fill station to fill the old siphon tanks I have.