Tuning SPA/Artemis P10 P15 P35 tuning
- Thread starter Loff
- Start date
I have been working with several members on the GTA site testing for both the P35 and Bullshark. The P35 has more room to work with so the inserts are sized a little different length wise. Here's one photo of the screw-in insert in my Bullshark and a photo of some of our testing inserts. When using the internal shroud insert the shroud has to be slid forward an inch or more depending on which gun you're using it on.
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Setting trigger for P35 is surprisingly easy. Took couple of minutes to set it like my FX Dreamline trigger.
P35 out of the box trigger is somewhere at the heavier side. There is two screws to turn to adjust first and second stage. The first stage pull weight spring also lightens second stage. And with the second screw You can adjust pull length of second stage.
Out of the box, the first stage (and second stage also) spring compression was like this:
I loosened the grub screw and let the spring push that brass piece all the way back. Then moved that brass piece forward by its length and tightened grub screw.
That thing alone made a big difference in trigger feel and pull weight.
Then decided to adjust second stage pull length as well. Adjusted it 1/2 turn (clock wise) from factory setting.
And that made my P35 trigger almost equal to my FX Dreamline trigger. So switching between guns is comfortable, regarding trigger.
P35 out of the box trigger is somewhere at the heavier side. There is two screws to turn to adjust first and second stage. The first stage pull weight spring also lightens second stage. And with the second screw You can adjust pull length of second stage.
Out of the box, the first stage (and second stage also) spring compression was like this:
I loosened the grub screw and let the spring push that brass piece all the way back. Then moved that brass piece forward by its length and tightened grub screw.
That thing alone made a big difference in trigger feel and pull weight.
Then decided to adjust second stage pull length as well. Adjusted it 1/2 turn (clock wise) from factory setting.
And that made my P35 trigger almost equal to my FX Dreamline trigger. So switching between guns is comfortable, regarding trigger.
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Ordered .177cal cleaning rod with rotating handle and managed to "measure" twist rate on my P35 barrel.
Drumroll - average from 3 measurements is 1:19.42., lets call it 1:19.
Used brass brush, because it engaged with the rifling the best and did rotate along the whole length of the rifling.
Drew a line along cleaning rod and marked corresponding mark to the end of the barrel. Then pushed brush as long as the cleaning rod did 1 full revolution. Then measured that travel distance and voila.
Pictures are taken of the first try when I tried to do that test with nylon brush, it was too soft and gave false readings. But the 1 full revolution length with the brass brush is correct and was same - 49 cm aka 19.3"
After that did some slug and pellet push through test, just because I had that rod to push them through.
All slugs went through quite well. NSA, ZAN 16 and 20, and H&N both were a bit tight at the choke. H&N 16gr was as tight as ZAN 20gr, seems like H&N lead alloy is considerably harder.
All others were OK.
All examples are shown on the pictures:
Lot of slug testing to be done. Did some hunting (pigeons) with JSB Monster RD-s and they do the job but they tend to go through. And based on that my aim is to dial to 10.03gr JSB KO or 13gr ZAN slug.
Drumroll - average from 3 measurements is 1:19.42., lets call it 1:19.
Used brass brush, because it engaged with the rifling the best and did rotate along the whole length of the rifling.
Drew a line along cleaning rod and marked corresponding mark to the end of the barrel. Then pushed brush as long as the cleaning rod did 1 full revolution. Then measured that travel distance and voila.
Pictures are taken of the first try when I tried to do that test with nylon brush, it was too soft and gave false readings. But the 1 full revolution length with the brass brush is correct and was same - 49 cm aka 19.3"
After that did some slug and pellet push through test, just because I had that rod to push them through.
All slugs went through quite well. NSA, ZAN 16 and 20, and H&N both were a bit tight at the choke. H&N 16gr was as tight as ZAN 20gr, seems like H&N lead alloy is considerably harder.
All others were OK.
All examples are shown on the pictures:
Lot of slug testing to be done. Did some hunting (pigeons) with JSB Monster RD-s and they do the job but they tend to go through. And based on that my aim is to dial to 10.03gr JSB KO or 13gr ZAN slug.
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That's great information, thanks! My Bullshark loves 10.3 Knockouts. It doesn't like Griffin 10 or 11 grain or NSA 12.5
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I checked my Bullshark .177 today. I made sure my cleaning rod was rotating smoothly and watched the tape as it rotated. I'm getting 1:21 consistently over 6 attempts.
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I was only able to achieve half a rotation when measuring. I was getting 10.5 inches each time for half a rotation.
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I think it's either 19 or 19.5 inches. I'm not at home right now but I can measure it later when I am. I do know that it's slightly longer than the p35.
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I finally remembered to measure mine and from breech to top of the threads, I'm getting 19 inches.
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This looks very interesting. Can you add a 1/2UNF thread at the end, to add a silencer? Something like this:
The bottom end fits snug around the barrel, to keep it aligned:
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I'm sure it is possible to end in a 1/2 UNF but I would be worried about how strong it would be. Could it withstand normal handling? Seems like the plastic 1/2 UNF piece would be the weak link if the moderator got bumped. Keeping the in shroud and out of shroud portions in the same printed piece leaves their diameter larger for even more strength.
I may worry too much about strength after breaking my buckrail moderator for my Prod. Nice moderator but I was not gentle enough with it. On my P35s I push the shroud forward to have the moderator stay inside the metal shroud. That way they are protected. You can do the same thing on a bullshark but the gap at the back of the shroud will be about 1.5 inches larger. The support points for the shroud are the same distance apart as on the P35, however.
I may worry too much about strength after breaking my buckrail moderator for my Prod. Nice moderator but I was not gentle enough with it. On my P35s I push the shroud forward to have the moderator stay inside the metal shroud. That way they are protected. You can do the same thing on a bullshark but the gap at the back of the shroud will be about 1.5 inches larger. The support points for the shroud are the same distance apart as on the P35, however.
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Finally some finishing, 3D printed by Jake Bowman, parts arrived for my P35. First package went missing probably due to cyber attack to Royal Mail systems.
Anyway, low cheek piece, adjustable buttstock and that piece that covers cocking linkage below pic rail.
Now the gun looks finished. And that lower cheek piece makes a big difference. Now when I shoulder the gun, my eye is spot on with scope ocular. No excessive canting with my head.
Win-win.
Height difference between OEM cheek piece and 3D printed one is 5.38mm. And that makes a big difference in how the gun shoulders.
To get the original rubber buttstock off of the gun You just have to rip off the rubber part of it. Then You can see 2 screws that holds that grey plastic piece onto the stock. Unscrew those and screw on the new adjustable buttstock.
Now the gun looks complete in my opinion.
Before:
And after:
With that adjustable buttstock the gun feels completely different. The adjustments allow You to lock that position in what You can shoulder the gun, eyes closed, and then when You open sighting eye, You are spot on, no adjusting Your guns position to get that right eye relief.
Anyway, low cheek piece, adjustable buttstock and that piece that covers cocking linkage below pic rail.
Now the gun looks finished. And that lower cheek piece makes a big difference. Now when I shoulder the gun, my eye is spot on with scope ocular. No excessive canting with my head.
Win-win.
Height difference between OEM cheek piece and 3D printed one is 5.38mm. And that makes a big difference in how the gun shoulders.
To get the original rubber buttstock off of the gun You just have to rip off the rubber part of it. Then You can see 2 screws that holds that grey plastic piece onto the stock. Unscrew those and screw on the new adjustable buttstock.
Now the gun looks complete in my opinion.
Before:
And after:
With that adjustable buttstock the gun feels completely different. The adjustments allow You to lock that position in what You can shoulder the gun, eyes closed, and then when You open sighting eye, You are spot on, no adjusting Your guns position to get that right eye relief.
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Anyone here ever have the hammer trigger issues I posted about on my thread today?
Regards,
Roachcreek
Regards,
Roachcreek
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I didn't see your post and a quick search didn't find it. What sort of issue are you having?
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Did some hunting with my P35.
Pigeons, starlings and house sparrows are not here yet, so I had to hunt other things
Pigeons, starlings and house sparrows are not here yet, so I had to hunt other things
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