PP700 adventure started(Artemis PP700s-a)

[Wolverineshooter]

For my PP700 .22, I adjusted the regulator and the hammer spring, trying to get a decent string of fpe on the high site, around 15-20fpe. Here is what I got so far:

   Airmax 0.22      CMHP 14.3gr
   Pressure   fps   fpe
1   24   588   10.98
2   23   589   11.02
3   22.5   610   11.82
4   22   609   11.78
5   22   619   12.17
6   21   614   11.97
7   20.5   637   12.89
8   20.3   619   12.17
9   20.1   658   13.75
10   19.8   653   13.54
11   19.6   667   14.13
12   19.5   692   15.21
13   19   725   15.78
14   18.5   702   15.65
15   18   723   16.6
16   17.5   729   16.88
17   17   722   16.55
18   17   730   16.92
19   16.5   721   16.51
20   16   719   16.42
21   15.3   711   16.05
22   14.7   696   15.38
23   14   693   15.25
24   13   683   14.81

I only got 9 shots within 4%. Any thoughts on what should I do to improve?

[Techie]

That's what I've seen in this "regulated" pistol.  I think it needs to be taken apart and the regulator worked on, just like mine.

[Wolverineshooter]

That's what I've seen in this "regulated" pistol.  I think it needs to be taken apart and the regulator worked on, just like mine.

Thanks Mike for letting me know that I am not alone - what did do to the regulator to improve?

[dang3r]

You can crank up the power by doing some mods and by removing the crappy stock "regulator" but your shot count will be terrible as much as your es. This gun have lots of potential as a matter of fact, 40 joules/ 30fpe are easily achievable in my setup.

This pic is at 150bar of working pressure using 25.62gr bullets

[Wolverineshooter]

You can crank up the power by doing some mods and by removing the crappy stock "regulator" but your shot count will be terrible as much as your es. This gun have lots of potential as a matter of fact, 40 joules/ 30fpe are easily achievable in my setup.

This pic is at 150bar of working pressure using 25.62gr bullets

Thanks Andreas - so no regulator, just use a few middle shots, am I right?

[dang3r]

Unfortunately no, my gun is heavily modified compared to stock pp700. But before i went hpa route I done the mods Donny (the original creator of this post) describes in first pages also completly removed the "reg", tuned the gun and was making 30 shots of 21fpe with acceptable extreme spread. The thing is that  this gun best preform in 150bar range.

 my current setup

[LeE]

Ha, I knew you could do it. Let me know when it moves into production ;-)

I will begin this weekend. I am going to have two diffent configerations. One is a short rail section about 1.250" and the other will have a full length under rail with two mounts that will be under 6.00" inch length.

[Wolverineshooter]

Unfortunately no, my gun is heavily modified compared to stock pp700. But before i went hpa route I done the mods Donny (the original creator of this post) describes in first pages also completly removed the "reg", tuned the gun and was making 30 shots of 21fpe with acceptable extreme spread. The thing is that  this gun best preform in 150bar range.

 my current setup

Thanks. I will read the first page again. 21fpe 30 shots are fantastic.

[Fussell]

Ha, I knew you could do it. Let me know when it moves into production ;-)

I will begin this weekend. I am going to have two diffent configerations. One is a short rail section about 1.250" and the other will have a full length under rail with two mounts that will be under 6.00" inch length.

I prefer the short rail ( 1.25" ) so I can mount it as far back towards trigger as possible.

[R0B]

Unfortunately no, my gun is heavily modified compared to stock pp700. But before i went hpa route I done the mods Donny (the original creator of this post) describes in first pages also completly removed the "reg", tuned the gun and was making 30 shots of 21fpe with acceptable extreme spread. The thing is that  this gun best preform in 150bar range.

 my current setup

I'm guessing the second gauge that you've added to the body is to show the reg pressure?. Rob

[Rob M]

Unfortunately no, my gun is heavily modified compared to stock pp700. But before i went hpa route I done the mods Donny (the original creator of this post) describes in first pages also completly removed the "reg", tuned the gun and was making 30 shots of 21fpe with acceptable extreme spread. The thing is that  this gun best preform in 150bar range.

 my current setup

that looks awesome !

[Techie]

Thanks Mike for letting me know that I am not alone - what did do to the regulator to improve?

Greg, mine needs to be worked on.  I have not done it yet.  Here's something nervoustrigger wrote and what I will eventually try on mine.  He reported back that it solved his regulator creep problem:

I had taken it apart because it had developed a symptom of reg creep.  I found a bit of debris on the regulator's valve seat as the likely culprit so I cleaned it and then burnished the pieces together to help ensure a good seal.  Those pieces are the white washer and the tapered surface of the screw that passes through it.  For the burnishing, I used some J-B bore paste and some medium metal polish compound (in stick form; scraped some off with a razor) to make a slurry, and used a handheld drill to grab the shaft of the screw and spin it against the washer.
 
The Belleville washers didn't have any noticeable burrs but I went ahead and lightly smoothed both sides with 400 grit wet/dry paper, and lubricated them when I reassembled.  By the time I had put maybe 30 shots over the chronograph to dail in the regulator and hammer spring, it seemed to settle in nicely.  No sign of reg creep now.  Walked outside last night and put 3 shots over the chronograph to see how it was doing and they read 850, 853, and 849.  Can't really ask for any better than that.
 
I tried only once to back down both the reg and hammer to about 700fps (9fpe) but the ES was unacceptable.  That was shortly after I had reassembled so maybe I'll try again after some break in time.
 
In hindsight, it occurs to me that it might be worth it to try flipping the white washer upside down to help with the reg creep issue.  The two tapered faces that form the valve seat are not ideal.  They represent a fairly large area of coplanar surfaces, and the pressure must jam the screw hard enough to deform the washer to form a seal.  By flipping the washer over, the tapered surface of the screw meets with a small sharp edge of the washer, focusing the force over a much smaller area and thus making it easier to seal.
 
I remember someone saying their washer was upside down and to watch out for it but I don't know if he related it to a specific problem.  It certainly would have been easy to conclude it was incorrectly assembled because it seems obvious that the two tapered surfaces were designed to fit against each other.  But now I'm wondering if it wouldn't benefit from flipping the washer over.  If any of you guys get inspired to try it, please report back.

[Wolverineshooter]

Mike, thanks for the info. I googled and found the following, so I may try it first.

   
I use the Max hammer,minimum transfer port setting   March 11 2016, 7:54 PM

As a general rule-the flattest shot curve comes from 1st finding the "sweet" spot on a powerplant using a chronograph.

This is established using "base" or manufactures settings & doing a full pressure fill & shoot till the velocity drops substantially from the norm. Note the lower pressure & then note the pressure when the powerplant produces maximum velocity.

Then increase hammer spring to the maximum. Keep the fill pressure near the max velocity psi & screw in the transfer port till you get a velocity reduction.

Try a shot string it should be much flatter. Then from there you should back off the hammer until the velocity drops at the max velocity point. Try a full pressure shot & then add hammer spring till it regains velocity(if needed).

Basically you are fighting the pressure resistance with the poppet valve, strangling the airflow at its most efficient point & the hammer spring is set from there to minimize the velocity curve.

The regulator setting is typically just above where the shot count drops off at the lower end of the fill.


I try to make my homebuilt valves more efficient at low pressures so I can use a lower regulator setting=more shots before falling off the regulator. Your gun will tell you what it likes but you need a chronograph.

[dang3r]

Unfortunately no, my gun is heavily modified compared to stock pp700. But before i went hpa route I done the mods Donny (the original creator of this post) describes in first pages also completly removed the "reg", tuned the gun and was making 30 shots of 21fpe with acceptable extreme spread. The thing is that  this gun best preform in 150bar range.

 my current setup

I'm guessing the second gauge that you've added to the body is to show the reg pressure?. Rob

correct, it showing after reg plenum pressure

[LeE]

Ha, I knew you could do it. Let me know when it moves into production ;-)

I will begin this weekend. I am going to have two diffent configerations. One is a short rail section about 1.250" and the other will have a full length under rail with two mounts that will be under 6.00" inch length.

I prefer the short rail ( 1.25" ) so I can mount it as far back towards trigger as possible.

Definitely. The mount will be an inch with width and the section will overhang 1/8 on both sides which should enable the mount to be placed right up against the trigger gaurd.

[Rallyshark]

That's what I've seen in this "regulated" pistol.  I think it needs to be taken apart and the regulator worked on, just like mine.

Thanks Mike for letting me know that I am not alone - what did do to the regulator to improve?

If you want the easiest way to fix the regulator problem, get a Huma.  I know it isn't the most cost effective, but it works and works wonderfully!  The factory "regulator" is more of a bleed valve, and the regulation is hit or miss.  That isn't to say there aren't some great results out there from the factory reg, but it is hard to get them perfect. If you want it to be easily tuneable, without weird results, just get the Huma.  Everything you do will make sense then  

Thanks Mike for letting me know that I am not alone - what did do to the regulator to improve?

Greg, mine needs to be worked on.  I have not done it yet.  Here's something nervoustrigger wrote and what I will eventually try on mine.  He reported back that it solved his regulator creep problem:

I had taken it apart because it had developed a symptom of reg creep.  I found a bit of debris on the regulator's valve seat as the likely culprit so I cleaned it and then burnished the pieces together to help ensure a good seal.  Those pieces are the white washer and the tapered surface of the screw that passes through it.  For the burnishing, I used some J-B bore paste and some medium metal polish compound (in stick form; scraped some off with a razor) to make a slurry, and used a handheld drill to grab the shaft of the screw and spin it against the washer.
 
The Belleville washers didn't have any noticeable burrs but I went ahead and lightly smoothed both sides with 400 grit wet/dry paper, and lubricated them when I reassembled.  By the time I had put maybe 30 shots over the chronograph to dail in the regulator and hammer spring, it seemed to settle in nicely.  No sign of reg creep now.  Walked outside last night and put 3 shots over the chronograph to see how it was doing and they read 850, 853, and 849.  Can't really ask for any better than that.
 
I tried only once to back down both the reg and hammer to about 700fps (9fpe) but the ES was unacceptable.  That was shortly after I had reassembled so maybe I'll try again after some break in time.
 
In hindsight, it occurs to me that it might be worth it to try flipping the white washer upside down to help with the reg creep issue.  The two tapered faces that form the valve seat are not ideal.  They represent a fairly large area of coplanar surfaces, and the pressure must jam the screw hard enough to deform the washer to form a seal.  By flipping the washer over, the tapered surface of the screw meets with a small sharp edge of the washer, focusing the force over a much smaller area and thus making it easier to seal.
 
I remember someone saying their washer was upside down and to watch out for it but I don't know if he related it to a specific problem.  It certainly would have been easy to conclude it was incorrectly assembled because it seems obvious that the two tapered surfaces were designed to fit against each other.  But now I'm wondering if it wouldn't benefit from flipping the washer over.  If any of you guys get inspired to try it, please report back.

Flipping that white disc will result in a big pucker factor when you try and shoot it, because it ain't gonna shoot.  It will essentially seal up the air cylinder, and no air will even make to the valve.  You will have to slowly unscrew the air cylinder to until it starts to leak to get the air out(pucker factor).  Ask me how I know, haha.

[nervoustrigger]

Haha!  Okay thanks for clearing that up, Donny!

[Phillk83]

Yeah, that can a problem.
Look for a hard piece of wood with a nice cutted edge and insert this into the barrel. maybe this is enough to top the spinning.

Thanks for the idea. Litterally right after i posted that i gave it one more try and it came apart.

[Rallyshark]

Haha!  Okay thanks for clearing that up, Donny!

I wish I could say I know, because I was trying something new, but...  I found out, because I accidentally put it in backwards    There have been a few other worried individuals on the fb page that made the same mistake, so that makes me feel a little better.  Seriously though, putting the Huma in it was the best thing I've done when it comes to tuning and repeatability of tunes.  With the Huma in there all of the tuning changes do exactly what you'd expect, and it just generally makes life easier 

[R0B]

That reg looks like it should do the trick a bit better for sure!  You could also put an o-ring inside the piece that the white disc sits in.  There is one in the kit that fits perfectly around the edge of it around the bottom of the threads.  I gained a lot of efficiency cranking my reg up higher than need.  You want a good snappy report.  It will almost sound quieter than it should, which means the valve is closing before the pellet leaves the barrel, and it uses much less air.  I say try at 115-125 bar, and see what happens My new version is hanging out in customs right now

I've just ordered my Huma reg. I presume that the 'o' ring replaces the white disk and isn't fitted as well?. This site has cost me a fortune so far :-)