Artemis PP800 .22 - Tuning

[Long_Gun_Dallas]

Couldn’t you just put a couple less pumps in the 1322?

Oh, no, haha.  I can't even imagine getting a multi pump 1322 up to that power level!  This one in question is pcp.

7.6" barrel.  (picture is before I cut barrel)


@Knife
That's a sweet setup!  You might be the only one shooting slugs with their pp700.  First I've heard of at any rate.  That's awesome.

Pretty wild you could find that many scorpions as well!!

[Pelletjunkie]

Ha, you might want to omit the “13” from whatever that gun is. The 13 in Crosman talk always indicates a pump.

[KnifeMaker]

Couldn’t you just put a couple less pumps in the 1322?

Oh, no, haha.  I can't even imagine getting a multi pump 1322 up to that power level!  This one in question is pcp.

7.6" barrel.  (picture is before I cut barrel)


@Knife
That's a sweet setup!  You might be the only one shooting slugs with their pp700.  First I've heard of at any rate.  That's awesome.

Pretty wild you could find that many scorpions as well!!

I'm highly allurgic to their venom. We have two types here that I know of. The Arizona Bark Scorpion is the most toxic in the U.S. and we are eat up with them.


Better to find them before they find me.


the mounted Black light makes them glow a bright lime green at night. Can't miss them.  


I spread Damatious Earth in all the corners of the Shop and under the house. Totally safe for children and pets, but turns Scorpions into Jerky. I have not counted them in the total at all.

Once it gets on them, they can no longer breath and dries them out completely.

[KnifeMaker]

The slug I shoot in the PP700 is on the left. Here it is sized to .2203", however for the pp700 it is sized to .2160.


The two on the left are NOE sized down to .216, and the next one it the Arsenal sized to .2203.
the Noe version has a slightly shorter ogive and larger meplat. Both are sized down or copied from the Lyman 257420. both are very accurate.
The NOE is 29 gr's while the almost identical Arsenal is 31.7 gr's.


 The two on the right are Arsenal copies of the 257420. One is sized to .250 and the other as cast for the .257.


I just received the Arsenal and decked the mold. It shoots very well from the TJ's .250 barrel, while I have not tired it in the PP700 yet. They weigh in at 51.3 gr's.


The bottom one is the NOE CC1 sized to .2203 and weighs 38.8 Gr's. Accuracy with it in the Brownells .22 short liner barrel is outstanding!


While some one calimes to have designed the Arsenal version, in truth it is the last design by thy eVery Famous Elmer Keith. the Father of the .357 Magnum, , .41 Magnum, and the .44 Magnums. the Keith flat nose hand gun bullet is favorite to this day. No design has ever beat it for large game with a handgun.


the .257420 was designed by E. Keith for the 25-20 and 25-30 black cartridge lever actions of the time. It is still the favorite for Roo hunting by pro hungers in Aussi land.


Knife

 

[Long_Gun_Dallas]

Sounds like a case of just vengeance!  And also like something from one of those Alien movies, haha.  I didn't know they would glow like that!

I've heard Damatious Earth works for any anthropod?  I've used it before for ants and the like.  They didn't seem to enjoy it.

Those all look like excellent casts and bullet designs (essentially being the same design)  I'd love to try out a flat nosed slug in a larger airgun.  I was eyeing an evanix rex last night.  Still trying to talk myself out of it 😅  $500 nib and saw a long barrel for it elsewhere for 110. 

Does noe make sizing dies to order for custom spec?  Stands to reason you would have to size down a good bit for a pellet barrel for any hope of it working well. Of course, that's where measuring comes in.

[Pelletjunkie]

Might be getting a little off topic here guys. This is a PP800 help topic.

[skiron]

As promised, here is my latest update after some extra mods in my gun.

I decided to get rid of the factory tiny protruded valve stem and to change it with a longer one to see how it goes. I used the factory cp2 valve stem instead, which is a bit longer than pp800's valve stem, to see if a greater lift and longer dwell would make any significant increase in power and usable pressure range. I also put the end cap in reverse to gain some hammer preload, and also put some xtra washers inside the hammer for the same reason. Porting remains in factory dimensions (3.5mm) so no mods there.

So this is my updated shot string after the new modifications mentioned above:
*start pressure is 220 bar (3190 psi)
*test pellet is H&N baracuda 21.14 grains


Shot  FPS            FPE           BAR

1   547,0   14,05   
2   565,6   15,02   
3   579,7   15,78   
4   594,0   16,57   
5   599,6   16,88   
6   596,6   16,71   
7   618,0   17,93   190
8   586,5   16,15   
9   630,2   18,65   
10   656,5   20,24   
11   625,6   18,38   
12   659,4   20,42   
13   668,2   20,96   
14   663,8   20,69   140
15   645,0   19,53   
16   638,9   19,17   
17   617,3   17,89   
18   600,2   16,91   
19   578,4   15,71   
20   564,1   14,94   
21   544,0   13,90   70

Average FPE   17,45   
Average FPS   608,5   
ES fps      124,2   
ES %      18,59%   
Efficiency      0,8   

--------------------------------------------

Conclusions:

1) seems that the original valve (with the short valve stem) was indeed one of the reasons I was running underpowered...with the new longer cp2's valve stem that I used, the increase in power is more than obvious...starting 14 fpe and toping at almost 21 fpe...not bad for this little lego pistol with it's tiny airtube. So the extra lift & dwell with some xtra spring preload accomplished my target regarding power.

2) As expected, extreme spread is indeed extreme!!! 124 fps (18.59%) spread for this 21 shots string. But my desision for using a longer valve stem wasn't only to increase power, but "maybe" to allow me to use the bstalley mod with one or two o-rings in the valve's phase...so this should be the next thing to try to flatten the string. Efficiency also not worthy but I'm after max power for 14 shots so let it be..

3) Furthermore, since I only need 14 powerfull shots (2 magazines) I will put some more preload to move the "sweet spot" in the higher pressure range, and I'll also adjust the start and finish pressure range to make things a little better...after all this will be a max 20 meters pistol so if I accomplish an 8% ES will be happy enough.

What do you think guys?

[Long_Gun_Dallas]

Good progress!

I still think you should see how it shoots on a paper target before you stress too much about ES  🙂  (not to say you are).  The bstalley approach should yield some Improvements, and will likely get you where you went to be.

I've run shims on mine.  And neither one I have responded well past factory pre-load or length of spring.  In regards to hammer bounce (multiple valve openings for one shot)

I think you'll be very happy with the results, however, one you finish doing what you stated.

[skiron]

Well....in the end I couldn't resist my thirst for power so I ended in the tuning below....After all, this little pistol's purpose will be to accompany my 38fpe - 24 shots - 4% ES modified bottled prod for any "emergency" short range  shots....so I'm fine with 7 (1 magazine) pistol's backup shots.
Wanted something like evanix AR6 pistol but in a more compact platform (and much cheaper) so I'm satisfied with the result...(I also changed the huge wooden grip with the black one from cp2 to be more compact)

Here's the final string:
- Fill pressure 210 bar
- 29.94 grain H&N Pilledrivers (or 30 grain H&N Slugs HP if they prove more accurate)

#      FPS           FPE
1   593,4   23,42
2   616,7   25,29
3   632,8   26,63
4   660,5   29,01
5   656,5   28,66
6   638,5   27,11
7   606,8   24,48

AVG FPS: 629.3
AVG FPE: 26.37
ES: 67.1fps (10.16%)

[Long_Gun_Dallas]

You edged out my 25 caliber pp800!  Power wise, anyhow.  haha.  Nice work! 

I did detune mine a bit for less noise/more shots. (and smoother hammer cycle) 8 good strong/accurate shots. Peaking at 28fpe with 25.4gr jsbs

Have you put it on target to see how it groups?

[skiron]

Thanks Dallas! It turned to be a powerfull little sh**!

No... no group testing yet since I'm in search for a good red dot, but I will test in the next days and share the results

[Baco]

Thanks Dallas! It turned to be a powerfull little sh**!

No... no group testing yet since I'm in search for a good red dot, but I will test in the next days and share the results

are you alive skiron? and is this little monster still shooting? xD