Scott,
I'd be interested in what you find. I fire polished the barrel twice with JB and I think it helped. But you will undoubtedly remove the barrel and do a complete polish. I think it's rough but that's just a guess because I did not slug it or boroscope it.
I think it is just an upgraded, slightly, P15, but I do not have a P15 to compare it to so that is just what I hear.
I took the trigger assembly completely apart by mistake. I first tried to eliminate the first stage by adjusting the lever that transfers the trigger pull to the rear. I could do it but the safety would not work if I did. It is just a trigger block safety. So I put it back but possibly not exactly like before. In any event, it needed the length of the bar shortened 1/2 turn after ~50 shots and I did not diagnose that as the issue at first when the gun wouldn't fire. So I took it completely apart. The small parts look to be investment cast and were pretty smooth. Definitely steel like the housing. I thought the machining in the recess for the trigger parts was kind of rough so I filed it smoother. There is a nice little hole that seems designed to let you put a drop of lubricant on the sear engagement point. The only trigger adjustment is a 3mmx.5x6mm screw that adjusts sear engagement. I want a 8mm but messed up the McMaster Carr order so I will have to reorder one. The 6mm one will get the trigger to where I want it but doesn't stick out far enough to use the lock nut. I could put a drop of blue locktite on it but prefer to just get a slightly longer screw. The rod I was messing with the length of has a really tiny C-clip on it that you have to remove to change the length or remove the trigger assembly. I lost one and ordered 100 replacements.
I have not taken anything else apart except the butt pad (to lengthen the pull). The rubber part of mine popped off the grey piece at the top and then slid off at the bottom. The grey piece is secured with two screws. I will probably order a replacement butt pad to lengthen the pull without the wood spacer I added. There is a guy, I think he's in England, that prints them whatever width you want. He also offers a lower cheek piece and a few other things. I found his website in the Artemis facebook group.
I did modify the moderator based upon Aaron Cantrell's design (he does youtubes). It was surprising how much difference it made. I went from 85-88 db to less than 70db but left the gun at about 75db. Aaron just cut really cheap hair curlers from the dollar store, cut in half, with felt and then put them into the metal baffles that come in the moderator. You can slide the moderator forward to use more of these curler/baffle combinations. The quietest was about a 1 7/8 longer gun for me. I left it with one less combination and less than 1/2 inch longer than stock. With another one removed I can be stock length but still at least 5 db quieter than stock. For backyard use, I thought stock was OK for me but 10db less is even better to avoid unnecessarily alarming neighbors.
I also tried different hammer spring settings and think I improved accuracy with 1/4 turn less. I've read the regulator can be adjusted but you have to remove the end of the air chamber where the gauge is to get to it. And then have a really long screwdriver. Probably weld something up if I ever mess with it. The gun comes with the tool to remove the end of the air chamber. My regulator, on my 25, seems to be set about 110 bar.
Jim
