The Artemis PR-900/ Stormrider project

[Racing]

Albeit rather fresh to PCP i work on powder burners semi pro, for lack of better wording.
First PCP i got me was a used 25cal FX Impact Mk1, and still have it around. So to be able to play around a tad more i after that bought me an almost new Hatsan BT-65 Elite, which is still a work in progress. Also 25cal.

But.
Then we started debating what it really takes and that there ARE very "cheap" PCP´s out there. Namely the Artemis PR-900W and as an ad for one showed up, hello!



These ARE no doubt rather simple little airguns. No argument there, so when i got back to the shop.. well, we´ve got like an in door range of approx 20m so i sat down with it next to the LabRadar and let it rip.
To keep permit exempt we´re limited to 10J around here but.. noone really cares and at 10J you just about could run besides the boolit on track for the target. 



I MAYBE got like 10 shots off. The thing lacked its magazine but the single shot tray was there at least. But.. 10 shots until i degassed the thing and ripped it apart.

This is a Series 1 gun, with all its shortcomings. So the stock "barrel weight" i unbolted in a jiffy and turned myself a press fit adapter out of steel to be able to install a moderator.

First up started by turning a fresh TP which i drilled 4mm and let her rip again. Muzzle speeds sure went up, and simple calculations left me with approx 40J. All good i guess but sure not what we were after.

1st and foremost, the gun is to be used for pest control and 40J would no doubt handle that, and then some. But.. this is also a project to noodle around and learn.
So.
We soon arrived on that we´d push the envelope a bit.





Trigger on these things are not adjustable per se in stock form. True, there is a small M3 grub to take out creep to the best of ability but.. Anyways. I soon opted to install a much less powerful trigger return spring. Sure... helped, but to be honest the trigger on these things ain´t exactly all that.
Nor is it to be expected in my opinion seeing what these guns carry as far as hang tag. This particular one in turn even cheaper as it was used, while far fram A-bused.



As word of advice to other 900 owners, the muzzle crown and chamber jobs looks like someone pulled them while putting out a fire at the other end of the factory.
Both the crown and the chamber, as well as the "forcing cone" has to be the worst such factory jobs i´ve ever seen.
Shoved a couple of pills through the barrel to get a feel for the rifling and choke.. and the choke starts about 20mm in from the muzzle. Rifling seemed nice even, and the effort pushing the pills through it was very uniform.
I did however have my doubts as far as that choke, but as it turns out.. my bad. The choke on the Hatsan BT for instance is shorter (approx 10mm in) but way more so. Ie; the BT chokes the barrel end way harder than this Artemis.
Anyways..
Fresh crown done on the lathe, and the final job i did with the now fresh press fit adapter in place too - of course.
Chamber then..

Well. I drilled the port out to a full 5mm and of course did the same to the receiver... in turn the transfer port and finally the actual valve itself too.
As i drilled the port in the barrel i deburred that on the lathe while polishing the chamber in itself out meanwhile. Ended up using 800 grit with thin oil.

As it turns out these small jobs made for a rather profound difference in accuracy.



Then.. the valve. At first i fooled around with just making fresh poppets for it until i reached ways end.. Sure. Made for a difference but really not all that in hindsight.



Yeah. One of like 10 different iterations. Noodled around with that there for quite a while before i went.. F-it. This whole idea of a softer seat installed to the poppet working against an anodized seat directly on the valve housing.. nah.



Ditto. These guys, as you´re probably aware, lack any and all seal on the actual valve pin that the hammer hits. So i countersunk the housing with an end mill and then turned like a "lid" with a small divot on it, the divot then being the part that puts pressure on the now installed o-ring.
Works rather well actually.



The inlet "port" of the valve saw modification too, of course, and have done so for a few different tries. Where we´re at that thing carries an easy 100% more port area vs stock.

More on that later though.



Indeed. 1/2"UNF. Thing is, i make my own moderators too, which has become a journey in itself. That though starts with a sound foundation, why i´ve found that it´s always a smart idea to keep that adapter all steel.





Now. As much as i always opt for function before form i had grown REAL tired of that rather "plastic" feel to the stock. To *(&^ with it and out the sander came. Good call as it turns out cause the reason for that rather plastic feel, it simply stems from the very very liberal use of grain filler coupled with that.. whatever the top coat is.
Underneath tho was this rather lovely piece of beech wood! Who knew!?!



Where we´re at this there is a work in progress too. Layer upon layer of linseed + turpentine. Truth be told i´ve by now reached the point where the stock shows sign of being fed enough why i´m currently just passing time as far as this to let the linseed cure at the pace it sees fit.
That and.. oil sanding the piece on intervals with the fine grit stuff. As far as that.. currently reached 1200 grit...



1/2"UNF indeed. So at first i just borrowed the can from the BT-65.. which kind of DWARFS the Artemis! 
Good times to come though.

At this point i had mixed up a reasonable hammer spring setup. A progressive such, where the mainstay is the hammer spring for an FX Impact which is coupled up to a way shorter and slightly softer generic ditto. This worked rather well, albeit on the edge as far as power needed to cock the thing.

So there i was, shooting the thing indoors and at this point wanted to evaluate where my new "knee" was at and what not right...

The actual valve then? What happened there? Well. After all them tries i said to *(&^ with it and chucked the housing into the lathe and out an end mill came. Took it to 12mm flat and then turned a seat out of POM with a massive 3/10mm press fit. Through hole now of 6,5mm and the fresh valve pin i made out of hardened steel.
MASSIVE difference to say the least and truth be told i might very well revisit this there need be. From the looks of it though THIS is where the gun changed face.
For real.



A series 1 gun right? Yeah. You´ve got it, there i was minding my own business when this "made out of chineseium" bolt handle of course broke. Turned a fresh one in a jiffy and back at it..
Numbers the LabRadar showed me were VERY promising! I mainly (read - basically only) shoot the JSB 25,4 grain heavies OR the JSB 25,4 grain Knock outs out of this thing and we were at an EASY 70 Joules at this point - while FAR from done.
Of course it friggin GULPED air, and doing so on a tank of a mere 100cc´s.. you do the math. LOL



Them stock barrel bands have sure been debated to death, if nothing else here on GTA, and as i had installed that press fit adapter for a 1/2"UNF thread up front.. no can do in stock form anymore.
So what i did was cut the utmost top off with a Dremel and installed the thing. The cut left me with a pair of "claws" that basically pulls the barrel in per original idea as you tighten down on the screw of the band between the barrel and tank.
Now.
I´ve played around with tightening that and not a BIT thus far.. but plz read on..



Yes. The barrel had seen a tad of TLC thus far and from previous experience i know how imperative these jobs can be for accuracy. Granted.. that there is a mere 20 meters but it sure shows promise. The flyer is on me in turn..
The thing will shoot, that much is for clear though and i believe we need to keep in mind that this PR-900W is the el-cheapo PCP gun of all.
It´s anything BUT an Impact but at 20 meters, with a muzzle velocity of now approx 960-970fps, it sure will shoot on par.
If i was impressed?
Take a WIIIIIIIILD guess.





Indeed. I make my own moderators. True.. i´m a tinkerer at heart why the actual development process to me is a journey in its own. That massive 55mm diameter can of the Hatsan was simply out.. Why i for the Artemis came to end with a 32*2mm one.
This time out with baffles inside though, which was a first for me.
So turned some discs out of POM/plastic and reasoned best as i could for asymmetric placement thereof. The basis of its innards being a perforated aluminium tube that i make by driving that "sheet metal" with a hammer around a matrix of 8mm diameter.
Then, the spaces "in between" i filled up by rolling piece of regular Wettex rag around said tube..then for one of the baffles.. another piece of Wettex.. and so on.
All in all 5 baffels and thereby 6 "compartments". The first one, where the bullet enters, by far the largest.

On that note i´ve come to wrap the moderators of mine with regular hedder wrap. Thing is see that i early came to react to that the aluminium left off a *ping" as i shot the guns and this *ping* about disappeared as i wrapped the tubes.





Yep. A rather long one, as i wanted ample room to play around within. As it turns out though this home brew can is rather effective. To the point where we, at approx 70 Joules, only hear the hammerspring as the gun is fired. Neat, as i had my heart set on a shroud too from the onset.
Might still be i fab a shroud for it too, but from a sound level POW no need what so ever.



So. So this is where i went astray a little. As the gun is as cheap as it is it didn´t really concern me whatever came to mind as any major loss would be the work invested.
But..
Time for a new bolt handle.



Wanted something WAY more to hold on to so.. Thing still was though that the thing bolted up via a pityful M4 hole on the bolt..and seeing the hammer spring pressures i´m working with.. nah.



So i put the receiver on the mill and widened that track to 6,8mm. In hindsight.. could have been smarter. That these guns are cheap, it HAS to show somewhere and if anywhere.. parts ain´t exactly close tolerance.
So having cut that track that tad wider made for more slop on the actual bolt. Daaamn...



Remedy, or band-aid more probably, was to drill and tap for yet a couple of M3´s.. which indeed did the trick. No more slop..and the hole for the bolt handle was now at least an M5. Still in single shear tho, which is an absolute moronic setup to begin with.



Stock had been "complimented" with a small pic rail at an early state, hence the bi-pod. Keeping with the original idea of the gun though the bi-pod was kept a cheap copy.
Works too i guess. Maybe partly due these guns being as light weight as they are. Even a low life Harris copy makes for a rather profound difference, of course. No bagriders and such tho.



"Air guzzler", indeed. At first there i had the Hatsan solution in mind to hinder hammer bounce but see, these guns lack provision to alter hammer spring tension in stock form, and redesigning that for a gun as cheap as the Stormrider?
Nah.
So instead i opted for a SSG setup, which really DOES make for a difference. To make this work though..
 


Which of course rendered a cut in the stock for the pin to protrude.



Then again. That end plug.. here we go as far as lack of fit again. So with all the chips down i turned a fresh one that actually FITS the "dang" tube. Made the through hole 6,5mm and in turn the pin extension (no pic of that yet) for the SSG 6,3mm. In short the SSG setup is "controlled" a´la a bearing, sorts of.
This had all KINDS of positive effects.. had to reset the trigger, which is adjustable by now. I started seeing REAL nice numbers vs pressures on the LabRadar and what not. WAY less air consumed.

On that note i came to modify the sear and as i did i wanted to mark the thing before drilling into it right? Well guess what, again.. chineseium so of course it broke.
Lucky me though i own a TIG welder too so a few moments later it was not only back together but sported a M3 hole for a grubscrew to set creep and let off point at the sear instead, making the set screw on the trigger blade now an adjustment for 1st stage take up.
With the SSG in place WAY better control was at hand, making for an all in all WAY better trigger.
Match quality though it is of course not but..

Then for the next issue, which was the pressure gauge. As i filled the tank up i never gave it a second thought really then i sat down and checked vs the calibrated gauge on the scuba tank.
But seriously?
At a mere 100+ bar the gauge on the gun told 160. But for the love a gaaaawd..

So? While i believed i checked performance at 200 bar fill pressure, yeah well you do the math. Thing is i use scubas only and they need to be filled up here after the hollidays why there at the moment is a mere 100 bars left in both of them.
Seeing that though the little 460mm barrel still hands me around 820fps at that TRUE pressure.

So truth be told this p-ssed me off to where i called a friend tonight and bought me a Yong-Heng. Not the solution to all ills i guess, but sure better than being stranded due hollidays.

Yes. As the story goes lads, to be continued and if nothing else a story on what can be had from these el-cheapo 900/Stormrider deals

[Racing]

Further plans?
Glad you ask, cause yes.

As this thing had evolved i´m now at a place where that 100cc tank is becoming an issue. Still do not know where we´re at performance wise due the original pressure gauge fooling me, so it´ll be a REAL hoot to see what comes out the other end at 200 bar.

Mind you, the adjustability of PCP´s. Thus i´ve got this thing standing around on a day to day basis set to them 10 joules, and just turn that up when need be. Like when going after rats.
Got to love that. 

That said though, as the stock tube is out of steel i´m now giving thought to adapting a "buddy bottle" of say 350 to 480cc´s somewhere, including a regulator.
That would be a mod that makes the gun change face no doubt. However.. rather happy with the looks of it as is and the install of a such a bottle would no doubt change that.
In turn, it´s rare that i´m more than 10yards away from the scubas..
In short, undecided on the matter yet and i guess i´m in no hurry to make the jury come back yet. Such a bottle and reg, cheap though and would indeed alter performance in a manner where i guess there´s no turning back.

[Back_Roads]

 Wow Real wood under that blonde coating, night and day difference, as well as you performance mods, do to it also.
https://i.postimg.cc/kX84R6Vn/1.jpg[/img]

[Racing]

Yeah!
Who knew?
What the pictures do NOT tell though is the rather profound difference in feel.

I for one happen to like "walnut n steel" why stripping it of its original finish was a no-brainer. No matter the outcome really.

But a bit of dye and liberal amounts of linseed? Yeah. I´d say that, and then some. 

(Sry for all the editing, my keyboard works a bit so-so and leaves various keys out at will)

[Racing]

That said guys.

On that buddy bottle idea. You know, a´la the Impact and what not.

As stated i kind of like the way it looks now and that would certainly to an extent be ruined by a massive added bottle out front.
Not to speak of added weight.

But.
Would YOU go the route of doing that mod or not?

[Spacebus]

70j!? That's crazy from such a tiny platform!

I am making about 36.6j with nothing but an Altaros regulator, some flattened pellets added to the backside of my hammer, and all of the porting matched at 3.5mm. I'm not using the gauge block and instead have an aluminum sleeve donated by a member of the forum.

I'm anti-bottle on the full stock rifle, but I have a spare Bandit tube with a drop block already fitted that I bought from a forum member. Eventually I'll put a small bottle on it and use my long .22 Chaser rifle barrel and the stock.

[Racing]

70j!? That's crazy from such a tiny platform!

I am making about 36.6j with nothing but an Altaros regulator, some flattened pellets added to the backside of my hammer, and all of the porting matched at 3.5mm. I'm not using the gauge block and instead have an aluminum sleeve donated by a member of the forum.

I'm anti-bottle on the full stock rifle, but I have a spare Bandit tube with a drop block already fitted that I bought from a forum member. Eventually I'll put a small bottle on it and use my long .22 Chaser rifle barrel and the stock.

Uhu, then again credit where credit´s due.
What?
I guess what to a large extent sets the limit for these guns is the after all limited port diameters. Now, with a past within the racing industry we could go on and on about flow and porting.. but i digress.
Point here still is though that i opened the channels up to 5mm flat. That´s a rather large difference in area vs the stock 3,5mm setup.

Worth it?

Well. Let´s turn this around a tad. The gun is set to a maximum of 200 bars for the tank right. That said these early guns lack any and all regulator and as such, seeing the limited capacity and the performance of them what would be the use?
However, and this is IMO where this gets a little interesting...
Due being fooled by that "non calibrated" Mickey Mouse gauge on the gun it has led me to shoot a tad around the 100 bar mark. With 25,4 grain slugs and 100 bar we STILL see approx 820-830fps.
Simple math tells that we´re at just over 50 Joules at that point. 50 Joules@100bar.
Now THAT IS interesting cause with the rather limited tank that would render that you now DO install a reg and set that to say 100 bar on a 200 bar fill.
That´s a pretty far cry from the stock 3,5mm openings isn´t it? In turn with the OPTION to turn it up at will. Where that´ll take me is anybodys guess right now and i will of course report back.

Mind you. This is with the "vastly" redesigned seat valve too. Valve seat through hole is of current at 6,5mm. Hard mod to do? No, not really but it does require access to a lathe - at a bare minimum, period.
So i guess this per always comes down to intended use, but that i came to see those powerlevels at those reduced pressures due these jobs.. no. I didn´t see that one coming, nor was it the intent.

I think we still need to keep perspective here though. The Artemis PR-900/ Diana Stormrider is a rather cheap PCP rifle. Thus, apples and apples why hotroding the thing, at least IMO, becomes sort of a quest in itself.
Bang for the buck, in the true meaning of the word.

Am i at the very least considering the install of a regulator to the stock tube? No. Not really, the intent of this piece is pest control, why i want it to produce power( or more to the point from a practical point of view speed) to make them hollowpoints open up direly on impact.
Thus.
If i´m to reg the piece i would want it simple adjustable. Ie; from the outside. Enter... aftermarket buddy bottle that for instance can be set to 2200psi as a happy middle.
At that pressure i´m absolutely certain the performance out of it would suffice, and then some.

[Spacebus]

I started out tinkering with a .177 Bandit with Altaros reg wearing Chaser Rifle barrel, grip, and stock, but then I found a .22 pellet mold and wanted something capable of shooting those. While tinkering with the .177 setup I also bought a bandit air tube and played around with that. Most of my mods have been focused on reach max advertised power for more than a few shots. The Bandit/PP800 and Stormrider/PR900 are decent PCP's out of the box, but the lack of consistency shot to shot was frustrating for me. 

40j would be a bit better for my 19 grain cast pellets, but I use my Stormrider/CR600W mashup for recreational shooting and the regulator gets me to 12 accurate consistent shots at enough power to push those 19 grain cast pellets with some authority.

For hunting/larger pest control I have a 101j .25 cal rifle and a 678j .45 cal bullpup, both of which are unregulated. The .25 can fire a whole eight shot magazine at peak power, but has an externally adjustable poppet for shooting lighter ammo at lower power levels for more shots per fill. The .45 only manages three full power shots per fill and has no power adjustability beyond running at lower pressures.

I look forward to seeing your results at higher power levels. I'm definitely running into the limits of what the stock valve is capable of, and glad to see someone messing with the exhaust valve. It seems that it was designed around the PP800 rather than the PR900, which I discovered by increasing hammer weight in my PP800 which just made it louder and not any faster.

This platform, at least with the porting less than 4mm, seems to make peak power at 165-140b regardless of what barrel you are using.

[FuzzyGrub]

Some very nice work to that platform!      

[Racing]

Hey thx!

@ Spacebus.
Uhu. Agreed. What i´m thinking here is that it might be a viable alternative to open the passages up on these rifles, reduce "plenum pressure" using a regulator and take it from there?
Again. 820-830fps@ 100 bar with 25,4 grain pills is rather to the point if you ask me. Point being that as either a target rifle or a pest rifle them 100 bar could easily be raised to say 120-130 bar for speeds that make a difference on impact - both scenarios taken into account.

Anyways.
Silent is good, we like quiet.



So, shroud time! 
In short, adapter on adapter. Steel of course, as the dimensions involved... well. Yes, the o-ring of course to "climb" one step and take support from that "wall" just ahead of the holes.
1/2"UNF inner to be bolted to the adapter, and in turn 1/2"UNF outer to take the moderator. Through hole of 8mm. I guess most of you know how a shroud works so...



Out rear a bushing out of acetal plastic that sports an o-ring groove to seal vs the shroud tube. Barrel is 12mm outside diameter, and that said it is on the plus side. So just drilling a 12mm hole will hand you a *(&^ of a time getting that thing onto the barrel, hence why i´ve sanded the thing both in n out on the lathe. As is a true slipfit on the barrel and in turn that shelf and o-ring handles business vs the shroud tube.
The bushing in turn getting support from the receiver rearwards.



N here we go. Yes, of course the tube is to see a bit of finish down the road, as it though it´s a work in progress so bare with me here... Tube is out of steel and carries 19mm outer and 1mm wall thickness. In other words 17mm inner, which hands us 2,5mm on the radius.. which´ll suffice just fine for the task at hand.



Uhu. Up front that adapter but.. just that single wall for the o-ring right? Yes. So i turned a small "shim" out of aluminium that sports like a small ledge that goes towards the o-ring, keeping the whole thing in place. That aluminium shim in turn isn´t going anywhere due the moderator.

I designed it like this to be "stand alone" so i have the option of running with or without this setup. The front o-ring in other words get installed AFTER the tube has been put on and thus less chance of ruining it.
The shroud tube "floats" between it´s endpoints with an axial movement of approx 1mm.

The stock barrel band in turn has been cut down rather severly by now, in essence just being a barrel shroud "support", to avoid any and all droop.
As is it juuuuust touches the shroud tube in idle.



Yeah, and an operators view. Mark the "T-handle" out rear, this will be dressed with a couple of bushings out of turned walnut i believe. In turn the protruding pin for the SSG setup.
Thing works really really well.
Btw. Cocking effort with that, still, rather ugly looking T.. difference isn´t something to joke about seeing the elevated hammer spring pressures i run. It makes cocking the thing WAY easier, which is all good seeing that this piece is to be used by an older man (not me).

So. That shroud of course stiffens the barrel up somewhat too. Difference in point of impact was sure there, have thus far just shoved a couple of magazines through it, but that was simple to cater for.
Difference in accuracy, which is the imperative i guess?

The rifle after all shoots very very well with only the moderator in place, so did accuracy suffer any? No. Not that i´ve noticed, mind you this indoors at a mere distance of 20 meters thus far.

Happy?
Yes. Yes i am. I for one find that there´s no reason what so ever for these subsonic low power (relative) PCP guns to go bang anymore than needed.
Quiet is good. We like quiet.

Thing is, it already is dead silent with that rather long moderator in place so the difference the shroud brings to the table..? Well, it DOES muffle sound even more. No argument, but as the rifle is as mouse silent already as is..
Will this shroud stay?
Dunno. Jury´s still out on that one. Want to be able to see what happens at like 970fps with those 25,4 grain pills before passing judgement.

If nothing else, now it´s there at least.

[Spacebus]

I'm sure the shroud helps with barrel harmonics at the higher power levels you are sitting at. With my heavier hammer weight my fairly large plenum is more of a dump valve. My "Bandito" has a CP-1/Airbug barrel, so no moderator and it is every bit as loud as my pneumatic stapler and nailer. With the short barrel every attempt I make at trying to dial in more power is rewarded with more noise and the same velocity. I'll be excited to see how much more power you make at 150b+ with the ported valve.

[Spacebus]

Oh, I also meant to say earlier that the factory barrel bands don't do much of anything, other than provide a pic rail if you add one. I can easily slide my barrel out with two barrel bands tightened all the way down. I figure they are just there in case you bump the barrel into anything.

Your shroud arrangement is actually impressive. I've been thinking about how to build in a shroud that will reduce muzzle report enough to not need the add on LDC to keep this thing short.

[Racing]

As much as i hear ya, i wouldn´t be to dead set on that there with harmonics.

For some reason it´s become all the rage within the PCP industry stiffening barrel installs up beyond belief (carbon fibre sleeves/shrouds and what not). I appreciate why but as always... there´s always more than one way to skin a given cat.
The presence of nodes and anti nodes is like a tuning fork, and can of course be played around with accordingly too.

Just compare the powder burners where no matter the caliber or load we always, at least if serious about accuracy, set load ladders up to figure out what gives. To make it work to our advantage. Differences might be slim as *(&^, but always there.

I was once taught that pressure = sound and sound = pressure. Thus where there´s a sound there will be a force, and this force will most likely carry a frequenzy. Thus.. "tuning fork" in this case.

We can "kill" that frequenzy best as we see fit til the cows come home, it´ll still be there so REAL question as i regard it (or the first one maybe more to the point) is if we´re to use it to our advantage or not?
Simple?
Noone said it was simple, which is the point.

As an, from the onset, aeronautic engineer i guess i could express it as either with or against nature.. right. Barrel tuners a´la the recent FX offering?
Sure. I guess.
But again, there´s more to it than meets the eye and one major aspect here, if you ask me, is the "o tempera o mores" that all solutions are to be fast and/or simple.
Well. They´re not.

Thus?
My take there with the shroud i setup as a stand alone. Basic reason for that, of course, to be able to unbolt the thing should it show to work against me (read - accuracy) in which case i´d drop that setup at the flick of a switch.
To mimic the basic idea though is dirt simple. In turn that front "shim" can be had to pull more than one task need be...

On that shorter barrel gun of yours in turn.
No matter it of course at a given point will become a limiter. That said though 150 bars might be but just as imperative is the flow capacity, which to be within realms.
At a measured 3,5mm i guess we can agree on that the setup stonewalls soon enough why an increase in both valve flow as port flow becomes a first hand choice, if you ask me.
5mm for that PR-900 rifle in 22cal is by NO means going overboard. Ditto for the 6,5mm valve throat, seeing the seat of the poppet being an outer diameter of 7,5mm.
Btw. FWIW. To cut such a poppet for THESE guns on the cheap out of decent hardened steel that´s available everywhere, just use a drillbit.
Cheap, simple, effective and available all over.

[Spacebus]

This is all beyond my ability, I have just a drill and a "drill press" attachment for it. If I could come by a spare valve and transfer port I would send it to you to enlarge the porting and make a new poppet. Theoretically I could do the barrel and breech with my drill and attachment.

[Racing]

We´ll figure it out 

Completely off topic, just got word that my Y-H compressor is to touch down next week. Thank GOD for that! Been feeling stranded as F here as the divers shop has been closed up to take inventory or whatever they´re doing ATM.


That said guys.
That idea of a buddy bottle.. Hm.
First thing´s first though and that is to try this thing out full pressure. Ie; what´ll happen at 200 bars.. It annoys the living daylight out of me that i got tricked by something as simple as a bad gauge.
Goes to show you though i guess.. as always. Tread gently, carry a BIG gun.. LOL

[subscriber]

Jesper,

I like your no-nonsense approach to making things work.  Also, your story telling style is clear and fun to read.

Some my frown on your header wrap over your moderator.  What many seems to miss is how much sound emanates from the outside surface of the tube.  It can ping like a wind-chime tube.  So, damping and shielding the outside of the outer tube, matters more than may be obvious - until you try it - which you have.

For a more elegant look (Should it matter), I suggest wrapping the tube in this material:

I bought some of this sound absorbing adhesive material for another job.  It works really well, when applied to thin steel that would otherwise ring or vibrate when struck:  www.amazon.com/gp/product/B01KZ5X7KO



Video of it working (lower the sound level before running the video):
https://m.media-amazon.com/images/S/vse-vms-transcoding-artifact-us-east-1-prod/v2/3255bca3-1dd6-53ab-bf75-a1b586df7ed6/ShortForm-Generic-480p-16-9-1409173089793-rpcbe5.mp4

[Racing]

Thx for the tip, and you certainly got a point.
Sound deadening material can be had about at any spares shop i guess? Thinking along the lines of color.. anyone you like as long as it´s black! 

Hedder wrap.. listen to this.
Very old close friend got hit by MS. An illness..ugly. Well. Yrs have passed and he nurished the dream of owning a trike. A VW motor powered one, for whatever reason.
So fall past we headed and bought him a trike. At the shop of mine he decides that the hedder wrap on that thing, bin time.
..and this happens while i just concluded what you speak of. "Aluminium pinging".
So. Nothing strange at all. LOL. Hedder wrap it is. ROTFLMFAO. Fastened with self tapping screws no less!

But yeah. It might look a bit off. I´ll grant you (and others) that much in a heartbeat.

[subscriber]

Your header wrap looks "tactical".  Some will like it for that; especially if it is in olive drab, flat dark earth, or camo

Seriously, I used to think that silencers wrapped in what looked like cloth were silly.  After all, "cloth" is flammable.  I thought such wrap must be for camo.  No, the official reason is to reduce heat shimmer, during use with a PB.  Either way; obviously the cloth must be as robust as header wrap, or it would not last.

Header wrap contains materials that would act as a thermal and coincidentally, a sound barrier - thus robust against heat for sure.

Now that I have seen how much sound comes off a thin walled metal LDC tube, the wrap also damps and shield this, to reduce the total sound coming from your location.  Especially, the ping - which shouts, "I am over here".

Next, wrap your air tube to prevent any remaining ping from escaping.    First, add a good depinger or regulator.

[Racing]

Right. That´s what i shoot.
We won. That simple. I got to get my scubas filled and put the foster to that adapter for the Artemis.... and opened the valve up.
Yep.
Now the gauge on the scuba met the gauge on the gun. 200 bar, thaaaaank you very much. Referenced and calibrated.

Performance?
Ah!! Yes! Well, as i regard it this has not by FAR reached roads end yet and i will certainly dwell on it further next couple of days/weeks.
That said however.. i guess we reached further than i expected.



Well. The LabRadar is stupid cause it has no idea how to lie. That there.. means 25,4 grains at 1017fps (highest number was 1024) which tells us that we´re in the 80 Joule region.
That ain´t cats p*ss for a 460mm barrel PR-900 in my book. Is it a "gas guzzler" still? I´ll reply, not as much as you´d think. As you can gather the numbers are fresh for the day and i DO work too right... LOL.
So in short these numbers are "out of the box". No tuning what so ever. Pressure drops like approx 10 bar per shot, you do the math. Played around ever so shortly with the preload on the SSG setup, which indeed altered performance.
In other words WAY more tuning to come.

What i aim to do next is actual porting, and i´m especially giving though to the exhaust port of the valve. That exhaust port is VERY crude as is and i´m absolutely certain there´s performance to be had by reshaping the thing - in essence from the seat out..through that 90 degree bend.
What i´m after is better flow in short, and i hope to see that at speeds of 1050-1070fps. Need be as this evolves go to heavier slugs as needed.

Happy?
More amazed really. Negatives? Yes. At these speeds accuracy came to suffer. Not major "waaaah it´s all lost!", but group size DOES open up which leads me to believe that the choking action of the barrel is now sorts of an issue.
Going from hole in hole to a 5 shot group of approx 1" at a mere 20 meters. So need to adress that.
I pulled a "de choke" stunt on my Hatsan BT with a Lothar Walter barrel, where i cut a bit of the end of the barrel off and in turn used valve lapping compound to "de-choke" what was left rendering that.. as a guestemate.. i got rid of like 65-70% of the choking action making that Hatsan a true tack driver with slugs.
Question i got for the wise men of Acron is if it is normal that the gun shoots tight at lower pressures and will open up as load/pressure increases?
Like i wrote one of the first sentances, i might have been around guns per se for the better part of my life, PCP guns though are semi new to me and i by FAR know it all.. not even CLOSE.
Hence me askin´...

That said we today got a lowly el-cheapo Artemis PR-900 to shoot 25,4 grain Knock out slugs at over 1000fps for a muzzle energy of 80 Joules. There you have it.

[Spacebus]

You are sending those pellets too fast to make tight groups, and the slugs don't like your choke. If you want to stick with pellets, try to keep them under 950 FPS. If you have an unchoked barrel then definitely go with slugs and take advantage of that high velocity, since you might be too powerful for any commercially available heavy pellets.