Power Plenum ~ Taipan Veteran



What all ammo have you guys been shooting successfully?

1577491340_20019036835e069b8cbb3f55.94962325_C9BE81A6-1C82-480C-8101-C30163404610.jpeg

I had great results with the NSA 29gr (932fps) 1.5 inch groups @100 yards, I’m gonna order some 26gr and try them on my vet and cricket, but first I need to install a plenum that I got for the cricket a while back lol



Renz.
 
Yet another update 😁 I threw caution to the wind; this is a high power .25, I thought, let her rip!!

I upped reg pressure to 142 bar. It’s now shooting the 33.95s at 918 fps and can easily go higher. For some reason, the gun prefers the original (MK1) JSB King Heavies when shooting hot. The Benji domes still shoot good but now have fliers as they are traveling at 990 fps on this tune!

I am now getting 36 shots on the reg from a 250 bar fill and can easily shoot another 4 shots that are tight. It doesn’t really start dropping until over 42nd, 43rd shot dropping into the 890s. The Vet just seems happier shooting at this power level.

I shot out to 83 yards in the wind and the 10 shot group looked to be less than an inch. It’s a bit stormy here today and I was shooting during a little break in the weather. More testing to come. Here is a quick 5-shot group from 40 yards. 
1577573721_3420761885e07dd59194532.18140322_4A5D3803-FA0A-4D0E-A69D-B4148EF00C68.jpeg

 
I decided to play around with my 22 cal Standard Veteran after fixing the 1/2oz trigger. Installed a plenum extension, Huma reg, and I made 3 different hammer springs to test out. I have my reg set around 136bar 145bar, thus far I'm seeing:

  • 24.8gr = 43.7FPE (891fps avg)
  • 27.5gr = 45.6FPE (865fps avg)
  • 28.5gr = 45.7FPE (851fps avg)
  • 33.0gr = 48.5FPE (814fps avg)

My bore is real tight though.. it's tough to seat any of them. I'm definitely going to have to remove a little material from the throat with my reamer. 

I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?

@sniperlabyo - I'm considering putting a 500mm or 600mm barrel on this build. What did you wind up doing for an adapter to attach your STX barrel on your Taipan?
 
I decided to play around with my 22 cal Standard Veteran after fixing the 1/2oz trigger. Installed a plenum extension, Huma reg, and I made 3 different hammer springs to test out. I have my reg set around 136bar, thus far I'm seeing:

  • 24.8gr = 43.7FPE (891fps avg)
  • 27.5gr = 45.6FPE (865fps avg)
  • 28.5gr = 45.7FPE (851fps avg)
  • 33.0gr = 48.5FPE (814fps avg)

My bore is real tight though.. it's tough to seat any of them. I'm definitely going to have to remove a little material from the throat with my reamer. 

I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?

@sniperlabyo - I'm considering putting a 500mm or 600mm barrel on this build. What did you wind up doing for an adapter to attach your STX barrel on your Taipan?

After degassing (I know, but have to say it) unscrew the air reservoir. Unscrew the valve-housing from the action using the provided pins. At this point, you’re there, as the valve and poppet are now exposed. The snap ring is holding the tension for the valve-return spring which I suspect is too weak from factory if going for low reg settings. 
 
Can this be done to an AGT Vulcan?

As Derrick said, yes it can. The Cricket plenum is very close. It will screw into the pressure tube, but the valve house will not screw all the way into the plenum. So either the valve house must be slightly reduced in diameter or the inside diameter of the plenum slightly enlarged. Or maybe if we’re lucky Ernest will start making plenum for the Vulcan like he did for the Veteran. ;)
 
I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?

https://m.youtube.com/watch?v=jlgx4TbLpu8

watched this and the 2nd video he has not sure it's what you need

https://m.youtube.com/watch?v=Jywlbafw_qk

unfortunately not English 
 
I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?





watched this and the 2nd video he has not sure it's what you need





unfortunately not English

I watched a couple of his videos, but never saw that second one. Perfecto, thanks!

I decided to play around with my 22 cal Standard Veteran after fixing the 1/2oz trigger. Installed a plenum extension, Huma reg, and I made 3 different hammer springs to test out. I have my reg set around 136bar, thus far I'm seeing:

  • 24.8gr = 43.7FPE (891fps avg)
  • 27.5gr = 45.6FPE (865fps avg)
  • 28.5gr = 45.7FPE (851fps avg)
  • 33.0gr = 48.5FPE (814fps avg)

My bore is real tight though.. it's tough to seat any of them. I'm definitely going to have to remove a little material from the throat with my reamer. 

I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?

@sniperlabyo - I'm considering putting a 500mm or 600mm barrel on this build. What did you wind up doing for an adapter to attach your STX barrel on your Taipan?

After degassing (I know, but have to say it) unscrew the air reservoir. Unscrew the valve-housing from the action using the provided pins. At this point, you’re there, as the valve and poppet are now exposed. The snap ring is holding the tension for the valve-return spring which I suspect is too weak from factory if going for low reg settings.

Interesting. I've had it in my mind that VDT has been too short. What's the lowest pressure that you (or anyone else) has tested? 
 
I got the transfer port out, but totally missed the fat little set screw holding it in place at first. I wound up with a small little gouge right on the sealing surface and had to put it on my lathe to polish it out by hand. I checked it after with my dial test indicator so it should seal once I get the barrel polished and everything back together, but damn that was an unnecessary step 👎

1577922491_8131974515e0d2fbb158d14.24090960_C5B3BD87-8F31-4B70-8119-B22AB85D2201.jpeg

1577922512_9989599185e0d2fd0cedb22.71447927_AB1B2A9E-A604-403D-BB42-9ED9C550E4E3.jpeg

 
I got the transfer port out, but totally missed the fat little set screw holding it in place at first. I wound up with a small little gouge right on the sealing surface and had to put it on my lathe to polish it out by hand. I checked it after with my dial test indicator so it should seal once I get the barrel polished and everything back together, but damn that was an unnecessary step
1f44e.svg


1577922491_8131974515e0d2fbb158d14.24090960_C5B3BD87-8F31-4B70-8119-B22AB85D2201.jpeg

1577922512_9989599185e0d2fd0cedb22.71447927_AB1B2A9E-A604-403D-BB42-9ED9C550E4E3.jpeg

Well crap. Hope it’s fine. You do have an exploded view in the owner’s manual (last page) for the Veteran. Most of it also applies to the Mutant. 
 
I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?





watched this and the 2nd video he has not sure it's what you need





unfortunately not English

I watched a couple of his videos, but never saw that second one. Perfecto, thanks!

I decided to play around with my 22 cal Standard Veteran after fixing the 1/2oz trigger. Installed a plenum extension, Huma reg, and I made 3 different hammer springs to test out. I have my reg set around 136bar, thus far I'm seeing:

  • 24.8gr = 43.7FPE (891fps avg)
  • 27.5gr = 45.6FPE (865fps avg)
  • 28.5gr = 45.7FPE (851fps avg)
  • 33.0gr = 48.5FPE (814fps avg)

My bore is real tight though.. it's tough to seat any of them. I'm definitely going to have to remove a little material from the throat with my reamer. 

I haven't seen any videos for getting the valve out. I want to get in there soon, am I right in thinking that the first step is removing the snap ring on the air cylinder side?

@sniperlabyo - I'm considering putting a 500mm or 600mm barrel on this build. What did you wind up doing for an adapter to attach your STX barrel on your Taipan?

After degassing (I know, but have to say it) unscrew the air reservoir. Unscrew the valve-housing from the action using the provided pins. At this point, you’re there, as the valve and poppet are now exposed. The snap ring is holding the tension for the valve-return spring which I suspect is too weak from factory if going for low reg settings.

Interesting. I've had it in my mind that VDT has been too short. What's the lowest pressure that you (or anyone else) has tested?

118 bar for me. 
 
I see what you mean about the valve spring. Bummer, I wanted to test with something stronger, but all my springs are going to be the same or slightly weaker. 

Anyways I'm glad that I took it apart. There was surface rust that I had to clean up on the valve pin and the hammer. My barrel also had some surface rust when I got it, but I spent a bunch of time polishing with jewelers compound from 7.5 down to 0.25 microns lol

Has anyone tried double stacking plenums in front of the reg? I have a second one that I'm tempted to test after ai get my Koi.

 
I see what you mean about the valve spring. Bummer, I wanted to test with something stronger, but all my springs are going to be the same or slightly weaker. 

Anyways I'm glad that I took it apart. There was surface rust that I had to clean up on the valve pin and the hammer. My barrel also had some surface rust when I got it, but I spent a bunch of time polishing with jewelers compound from 7.5 down to 0.25 microns lol

Has anyone tried double stacking plenums in front of the reg? I have a second one that I'm tempted to test after ai get my Koi.

The more plenum the better. The only reason not to have more is for those going for a low power tune, like under 20 FPE. You’ll just have a longish tube but I’d like to see your results. In fact, I'm going to do the same. Thanks. 
 
I see what you mean about the valve spring. Bummer, I wanted to test with something stronger, but all my springs are going to be the same or slightly weaker. 

Anyways I'm glad that I took it apart. There was surface rust that I had to clean up on the valve pin and the hammer. My barrel also had some surface rust when I got it, but I spent a bunch of time polishing with jewelers compound from 7.5 down to 0.25 microns lol

Has anyone tried double stacking plenums in front of the reg? I have a second one that I'm tempted to test after ai get my Koi.

The more plenum the better. The only reason not to have more is for those going for a low power tune, like under 20 FPE. You’ll just have a longish tube but I’d like to see your results. In fact, I'm going to do the same. Thanks.

Aesthetically it would work with the Koi, but thr Tanto would probably make the barrel and air tube look perfect. I don't think the Tanto is going to work though, I don't mind the air tube length with one plenum extension, but two would expose the muzzle blast beyond my comfort level. 

I've also thought about what the target power for this build, with the factory barrel I want to get it up to 54FPE with 28.5gr. My math tells me that 56FPE might be the top end without giving it a hernia lol, but I would settle for 52FPE. @jwrabbit123 has already achieve 52FPE, but he is shooting 36gr MP slugs. Shot count isn't higher prio than power for this one, as long as I can get around 2 mags - I'm happy with it.

BTW, for those that have cranked up power with a plenum + stronger spring + higher reg pressure, does your Vet make weird noises when the reg re-pressurizes? Mine sounds like it's wheezing, I think it's a combination of spring bounce and the atmosphere port filling with air. 
 
I see what you mean about the valve spring. Bummer, I wanted to test with something stronger, but all my springs are going to be the same or slightly weaker. 

Anyways I'm glad that I took it apart. There was surface rust that I had to clean up on the valve pin and the hammer. My barrel also had some surface rust when I got it, but I spent a bunch of time polishing with jewelers compound from 7.5 down to 0.25 microns lol

Has anyone tried double stacking plenums in front of the reg? I have a second one that I'm tempted to test after ai get my Koi.

The more plenum the better. The only reason not to have more is for those going for a low power tune, like under 20 FPE. You’ll just have a longish tube but I’d like to see your results. In fact, I'm going to do the same. Thanks.

Aesthetically it would work with the Koi, but thr Tanto would probably make the barrel and air tube look perfect. I don't think the Tanto is going to work though, I don't mind the air tube length with one plenum extension, but two would expose the muzzle blast beyond my comfort level.

What do you mean about the muzzle blast and the Tanto? I have my .25 Vet Long rocking 63.8 FPE with a Tanto attached.