PP700 adventure started(Artemis PP700s-a)

[Jimr65]

A tear down video is what we all seem to be waiting for... I have tried to suggest this on another British site but with no takers yet... The mods that are easily achieved (In order of ease, remember that this is written from a standpoint of a Brit limited to 6FPE for a pistol and 12FPE for a rifle or carbine) are;
Transfer port, wide open for power, possibly a bit nipped for efficiency??
Hammer spring tightened for power and decreased lock time but heavier sear engagement and trigger, loosened for efficiency and trigger feel but increased lock time
Trigger sear screw and trigger screw for trigger feel and engagement.
Regulator screw... Depressurize for ease of adjustment, small adjustments with a ground off Allen key and repressurizer before you can judge the effect.
Strip and port the valve, more power
alter the valve spring pre-tension, varied effects, some of which are not desirable. (low pressure operation)
Rebuild the regulator and mess around with bellville washer configuration (beyond my knowledge yet)
re design the valve with fewer holes and better alignment ( more power/ greater efficiency)
Enlarge the chamber on the regulated side of the gun before the valve (could be useful for power or efficiency)

There probably are more tweaks out there.. I would like one that makes it sound less like a flactulant rat by reducing hammer bounce.
Jim

[Wayne52]

The thread that was posted for the English pdf of the P700S-A was done by wimpanzee

https://www.gatewaytoairguns.org/GTA/index.php?topic=128048.0

and you even posted in this thread sawtoothscream, it was before you ordered yours though

[sawtoothscream]

The thread that was posted for the English pdf of the P700S-A was done by wimpanzee

https://www.gatewaytoairguns.org/GTA/index.php?topic=128048.0

and you even posted in this thread sawtoothscream, it was before you ordered yours though

Thanks, forgot all about that lol

[Kid Shelleen]

I’m trying to tune my son’s PP700S-A (.177) and could use some advice.  He wants around 600 fps with a starting fill between 2400 and 2600 psi.  I’ve tried a dozen different settings but am having trouble keeping the extreme spread down to a reasonable number.  I’ve got the transfer port screwed in (CW) about 2 turns from flush, just about where it’s starting to restrict the air a little.  The hammer spring is set at about two turns in (CW) from where the hammer spring starts to compress.  I arrived at these setting by setting the TP to full open and adjusting the hammer spring to full compressed.  I then shot two round, noted the speed and turned the hammer spring out (CCW), continuing this process until there was a noticeable drop in power, using that number (580) fps) as the speed I wanted.

What I have noticed so far is that all the settings I have tried seem to start low, move steadily up then drop down fairly fast.  I’m getting extreme spreads in the range of 50 to 90 not counting the first few shots to settle down the regulator.  The starting fill pressure also seems to make a difference too.  I would be grateful if someone has any ideas on what’s going on and how I can get a decent string around 580 fps.  Thanks.  Here’s the last string I got.

[bandg]

Seems I read that some of the European shooters were having similar trouble trying to tune to low power and that it was believed that it would function better tuned at higher power.   I'm going for faster myself so can't be of any help there. 

[nervoustrigger]

Mike,

Your string looks characteristic of insufficient hammer strike for the regulator's setpoint.  Toward the end, your velocity goes up and I presume that is where the reservoir pressure is falling below the setpoint. What it represents is that the hammer is able to create more lift and dwell as the pressure falls, resulting in higher velocity.

The best way to deal with that is to open up the transfer port restrictor (back to flush is good), then back off the regulator setpoint a bit and dial up your hammer spring preload until you find the maximum velocity.  Do that until you get a velocity of around 620 fps, then back off the hammer spring ever so slightly until the velocity falls to, say, 605fps.  Then screw in the TP restrictor until it drops that last little bit to your goal and that should give you a good shot count and low ES.

Granted, I am not familiar with the particulars of why others have had difficulty tuning it to low power levels, but your string as it stands now looks very much textbook of the symptom described.

[Rallyshark]

I think Jason may be right about the set point of the regulator.  You do have one thing right, which is starting with a 165 bar fill.  I think most of the European guys do a 160 bar fill for the lower power levels.  Like others, I haven't even attempted to tune mine at that low of a power level, so I can't offer any first hand experience for the tune you're looking for.  I think Ribbonstone has done some good low power tunes on these too, so you may want to shoot him a message.

[Kid Shelleen]

Thanks for the replies all.  Jason, thank you for the information.  When you mentioned the velocity going up when the reservior pressure falls below the regulator setpoint, if the hammer is too weak, that range a bell.  I remember reading that somewhere in the ton of stuff I researched on regulated PCPs.  I'll  try your suggestions tomorrow. Thank you for the help.  Mike

[Jimr65]

I was extremely lucky with my pp700. It was one of the good .177's (British bought).. straight from the box it was shooting 3.4 FPE. which was disappointing until I woke it up by opening the transfer port and setting the hammer spring (I can still turn the hammer spring nut with a screwdriver and the hammer has never marked the face of the valve...Having tinkered further the TP is screw is now protruding from the top of the breech block by 1 thread, weird, but the pistol seems less variable for me at this- might just be the reg settling in but I will leave it for now) The reg seems consistent right down to 70 bar and I am shooting 6FPE (just under for U.K law) 560 fps with JSB exacts. From a full 220 bar fill the gun is consistent to within 10 FPS across a 90 shot string all the way down to 70 bar....
I was  so impressed with this pistol (no leaks from the breech) that last Friday I bought a .22... I took it down the club straight from the gun shop, put it on the chrono, it leaked like a sieve from the breech, had a stupid spread with the 120 bar it came with and on the first 217 bar fill (all that was in the bottle) the reg jammed shut and air wouldn't pass to the breech to allow shots at all.... Back to the gun shop it went.

[Bizill]

What do we search for for the facebook group again?  I requested being added but must've been denied and I cannot find the group anymore.  I guess I ticked somebody off...

[Rallyshark]

What do we search for for the facebook group again?  I requested being added but must've been denied and I cannot find the group anymore.  I guess I ticked somebody off...

I doubt you ticked anyone off. The admin of that group is very  particular about adding people is all. Find me on Facebook(D Avery Sellers), and shoot me a message so I'll have your name. I will let him know you want to join, and he'll add you

[Wayne52]

I was subscribed but I ended up unsubscribing, facebook is &^^& IMO.  That group that I was in was the same one,  I use to go on facebook quite often but not so much anymore, it can end up becoming more of a chore rather than enjoyment.

[anti-squirrel]

I was subscribed but I ended up unsubscribing, facebook is &^^& IMO.  That group that I was in was the same one,  I use to go on facebook quite often but not so much anymore, it can end up becoming more of a chore rather than enjoyment.

This pistol is one of the only reasons I ever considered joining Facebook, but I enjoy this place more, the technical information is superb, and this way I don't have to join FB, so itza Win for me.

I'm very intrigued by doing a low-power tune.  As much as I enjoy hammering a squirrel in the nugget with a full-power-shot, it's massive overkill when I can put the pellet where I want with utter confidence inside 30 yards.  A 6 (or teensy bit more) FPE tune sounds about perfect.

[bandg]

Hope you get it beat.  I always like the overkill myself. 

[aluminumfetish]

I was subscribed but I ended up unsubscribing, facebook is &^^& IMO.  That group that I was in was the same one,  I use to go on facebook quite often but not so much anymore, it can end up becoming more of a chore rather than enjoyment.

^^^^^^    so true. There is not enough pistols on earth to get me on facebook. Scurge.

[Rallyshark]

What do we search for for the facebook group again?  I requested being added but must've been denied and I cannot find the group anymore.  I guess I ticked somebody off...

I doubt you ticked anyone off. The admin of that group is very  particular about adding people is all. Find me on Facebook(D Avery Sellers), and shoot me a message so I'll have your name. I will let him know you want to join, and he'll add you

Holy cow, I spelled my own name wrong,lol!  I'm D Avery Sellars on facebook(I spelled it ers the first time).  There is a lot of useful info on that facebook group, and is worth joining for that.  That is especially true for the folks looking for low power tuning info.  Of course there are countless other airgun groups on there too.  Anywho, if any of you shoot me a message on there to assist in the process of joining that group, let me know your GTA name so I'll know who I'm talking about please   The name of the group is "SMK PCP pp700w Pistol Owners Tuning and Modifications Group".

Maybe this link will work?
https://www.facebook.com/groups/135125473560570/

[TleVta]

Pretty much the main reason I go on FB is for that group. Klaus, the owner knows that pistol very well and documents his work in the files section. Very helpful for a new pistol owner. Some of those guys are making some nice grips. Want one, but not right now.

[bandg]

In the past I've mentioned trying to replace the thin breech o-ring with something larger to try to eliminate breech leakage.  I have shimmed between the valve face and the breech block to eliminate leakage there and so far it is working fine.  Rallyshark has faced the inner surface of the valve so that it can screw in slightly more for the same reason and notes that works and Schultz I believe has put a shim behind the barrel bushing to space it out again for the same effect.   But all of these methods leaves the thin stock o-ring in place which seems like it could be improved upon.  I'm thinking that a larger cross section o-ring would provide much more sealing surface area and might improve breech sealing without the need to shim anything or face the valve.  I received a bunch of o-rings today and disassembled the pistol to trial fit some.  With the barrel bushing removed, the breech end of the barrel is not threaded completely to the end and there is an area there that looks just right for an o-ring to fit flush against.   A 3 x 6 75D o-ring seems to fit perfectly into the space (and one of the 90D sizes is also very close but may be too hard).  The 75D is a snug fit over the barrel end and then requires a bit of a push to slide into the barrel channel so it should seal well against the barrel channel at the outside and the barrel itself at the inside.  Tomorrow I am going to try to get a replacement piece for the barrel bushing made that will be shorter by a sufficient amount to allow the thicker cross section o-ring to sit against it's face and be held out for pressure against the breech block.  I don't have a lathe or milling machine so making this piece may be something I have to have done at a machine shop but it isn't that complicated a piece and I may be able to get it done with the tools I have.  Seems like it might be worthwhile if it will improve sealing and possibly last longer than the thinner stock o-ring.

[TleVta]

Motörhead replaced his barrel and while he was at at he used a Weihrauch breech seal. Don't know how that would work, but I've got a spare HW seal and it's the same OD as the stocker. If I had any machinist skills, I'd try to do the same.

[Wayne52]

I got me one of Rocker1's newer version LDC's on the way soon