Regarding the scope rail, in my case I didn’t detect any misalignment issues however the 2pc construction made me leery about possible sensitivity to POI shift if I bumped it into something. I decided to install a 1-piece mount bridging the two pieces of the rail to lock everything together. I have not had any POI shift issues after a lot of handling so that seems to have been effective.
This 9 x 1.5 mm Buna N O-ring seems like the right one: https://www.mcmaster.com/9262K126/I don't know if a square section ring would be a silly idea due to the sweeping action of the breech: https://www.mcmaster.com/1171N153/ . I suppose that depends on the shape of the o-ring groove. I have not tried to remove mine yet.EDIT: This imperial one may provide the right "tighter fit": https://www.mcmaster.com/9452K21/ Closest metric size available at McMaster: https://www.mcmaster.com/9262K139/I am sure the O-ring Store has a wider selection, but I suspect that I can't have the parts by Monday
Posting here on the Darkside because the Chinese airgun gate does not seem to have PP700 threads, so no owners will see it there...I got a .177 PP700 from Krale yesterday. Was impressed at how quickly I could hand pump it, from completely un-pressurized, to the top of the green zone on its manometer; 200 BAR. Left it overnight to check for leaks. The needle did not move.After shooting two "wet" felt pellets and two dry ones I declared the very shiny bore ceremonially clean enough for lead pellets. I started shooting H&N 7.3 grain wadcutters because they seem to be very efficient out of many other platforms, probably due to low friction because their head size is .176". These shot around 670 FPS for 10 shots. Then I decide to try RWS 9.3 grain Supermags as a heavier version of the same thing. These shot at 615 FPS. After about 20 shots total, I went back to the 7.3 grain H&N wadcutters to see how close the velocity would be. Interestingly, the velocity had risen 15 FPS to 685. So, 7.6 and 7.8 FPE for the 7.3 and 9.3 grain wadcutters, respectively. I don't know if the velocity increase seen with the lighter pellets was due to the poppet valve breaking in, or evidence of less than perfect regulator action. Not enough shots to allow the mechanism to settle - so time will tell. The pistol arrived with oil on the O-ring face of the swinging breech block. I decided to leave it there. My first shot was over the chrony. I noticed what looked like oil mist spraying from the O-ring seal between the barrel breech and block sealing faces. After the first 10 shots I placed some tissue paper over the gap and fired a shot. As you can see, the leaking air cut a rough slot in the paper; indicating what I think is a significant leak.I was expecting the pistol to be loud, and it is. However, I am convinced that half the apparent report to the person firing the pistol is coming from the breech O-ring area. Improving that should reduce noise and improve performance and efficiency.When you push the closed breech block forward at the top edge, the apparent gap against the barrel face closes, with perhaps 10 lb of force applied. I tried shooting it over the chrony while pushing the block forwards. Once I figured out how to avoid having the hammer whack my thumb, a clean hammer strike actually produced a 100 FPS loss in velocity. Either tweaking the breech block opened the gap at the bottom of the O-ring, or perhaps the kinking load somehow partially bound the valve pin.The gauge pressure dropped from 200 Bar to 120 BAR after about 25 shots total. Not sure what to expect here yet, but am pretty sure that efficiency should improve, if the gross breech O-ring leak can be eliminated.So, the question is how to reduce the gap and increase the load on the O-ring? Is there a shim washer one can replace with a thinner one to close the gap? Is there a spring washer pushing the parts together; or how is the gap controlled beyond parts tolerances? Will the O-ring seat accept a taller O-ring?This experience tells me that screwing in the TP throttle screw will increase the leak; and as such is contraindicated. As noise reduction is one of my goals with for this pistol, throttling the TP will reduce pellet velocity, but in my case, probably increase noise exposure. Better to reduce what seems like a very energetic hammer strike. I figured that setting the PP700 up as an indoor 10 meter plinker, shooting at perhaps 5 FPE should reduce the report noticeably. Certainly, my IZZY MP-46M SSP pistol shoots these same pellets at 4 FPE, and produces only a muted pop, from a barrel that is 0.5" longer. As the PP700 is shooting 7.5 to perhaps 8 FPE, it does not seem that it would be as quiet as the 46M when detuned to 4 FPE. Not until the breech leak is reduced by 98%. The 46M does not have any kind of air stripper. Just an exposed muzzle.So; I either want a quiet indoor 10 meter plinker, or an outdoor "ratupuncture" with 10 to 12 FPE. In the latter case, I would investigate ways to improve the shroud. Either way, tuning strategies would be appreciated.General comments:Pellets load almost too easily into the breech. As if the land diameter is on the large end of the spectrum. Admittedly, this is with pellets having head diameters on the small end of the spectrum. .177" head diameter pellets should be "perfect".Trigger is very heavy compared to the IZZY SSP. More like an out of the box Weihrauch springer. I like the fact that there are sights; even if there is no elevation adjustment.Overall impression; a very nice airgun for the money. Will need a little bit of intervention to make it closer to perfect.https://www.krale.shop/en/artemis-pp700s-a/
it sounds like you need a HW40 instead of that high velocity pcp
Quote from: James340 on September 14, 2022, 07:13:23 PMit sounds like you need a HW40 instead of that high velocity pcpThat is a great suggestion, James. But I am on an airgun buying diet I see AOA is selling the HW40 at what looks like a good prince: https://www.airgunsofarizona.com/pump-up-pistols/weihrauch-hw40/My favorite SSP pistol is my Baikal / IZZY 46M. It has a very gentle charging effort due to the extra linkage charging handle - especially considering it shoots at 4, rather than 2.5 FPE for the HW40. Yes, accuracy matters more than power, but I like both - if I can get them with low effort cocking. Else, I have a number of Beeman P17s - a clone of the HW40. I like everything about the HW40 feel and shooting experience; except for the way the cocking handle (barrel / "slide") slams shut as it closes. The top section is over styled and not pretty; but neither is the 46M. The simple HW40 grip is immediately comfortable, while the 46M grip panels require massaging to fit, and the grip angle may not appeal to everyone.
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