Modski66
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Post by Modski66 on May 15, 2023 19:14:33 GMT
The new-to-me PPK/s is proving a bit of a challenge for my frazzled grey matter. Everything on it looks and feels perfect, but with a new co2 capsule in, it just runs out of puff after six or so shots and does not have enough oomph to cycle the slide and cock the hammer, even waiting five seconds between shots. I have had the valve to bits, nothing amiss, enlarged the port in the piercer and drilled all the way through the filter (I have a spare) but still no joy. 😢 What am I missing that could cause this? Just to be clear, I am not in the slightest bit annoyed about this with bb1975, he was very clear that there were possible issues with the pistol, and is a real gent to deal with. In fact, I am really quite pleased that I have a puzzle to solve (maybe with a little help) and something to tinker with. 😁
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Post by HeadHunter on May 15, 2023 19:40:35 GMT
A couple of questions buddy.....
Is it emptying a CO2 entirely after 6+ shots ?
Is the main firing valve sealing off properly after the shot ?
I'm going to guess that it's venting gas down the barrel, which would be difficult to tell in normal use as you're pointing it away from yourself (if you aren't then you are definitely doing something wrong, lol). I don't know anything at all about the valve system in a PPK but all valves obviously have to open and close, I'm guessing that something is obstructing or slowing the close cycle of the valve which could cause heavy CO2 loss.
If it was losing CO2 anywhere else on the gun you would have noticed it (the sound and the freeze factor), it could be freezing the valve causing it to stick open for longer too which is just compounding/exaggerating the original problem.
My suggestions can be taken with a pinch of salt as (like I stated) I have no experience whatsoever with the 'Bond' gun.
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Post by bb1975 on May 15, 2023 20:07:19 GMT
Ah thanks Mark, it's a really odd one.
To add context for people smarter than me to whom it might be significant: for me there had been an audible leak every time I loaded a co2 capsule, (but which seemed to stop after several shots) until the day of posting, tested it that day and no (audible) sign of a leak, which was weird enough.
I hope you get to the bottom of it and if not (or if it's an expensive fix) drop me a line and we'll sort something out.
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Modski66
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Post by Modski66 on May 15, 2023 22:28:44 GMT
Shaun, it still fires after six shots, but the fps is down and the hammer isn't cocked by the slide, so it's thumb operation. It's like it can't get the co2 into the valve fast enough. There are no leaks on it whatsoever, not even when gassing up. I am beginning to wonder if it's something like the recoil spring being too 'strong' or too much friction somewhere, it doesn't feel heavy or over-sprung though. One thought I had was to add some packing under the hammer spring, but that would more likely consume the co2 faster, so I didn't bother. Brian, no need to come to any arrangements, the deal is done and I am a very happy chappy. Anyway, it's my little fun-gun now, and you are not having it back! 😝
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Post by HeadHunter on May 16, 2023 8:36:34 GMT
Shaun, it still fires after six shots, but the fps is down and the hammer isn't cocked by the slide, so it's thumb operation. It's like it can't get the co2 into the valve fast enough. There are no leaks on it whatsoever, not even when gassing up. I am beginning to wonder if it's something like the recoil spring being too 'strong' or too much friction somewhere, it doesn't feel heavy or over-sprung though. One thought I had was to add some packing under the hammer spring, but that would more likely consume the co2 faster, so I didn't bother. Brian, no need to come to any arrangements, the deal is done and I am a very happy chappy. Anyway, it's my little fun-gun now, and you are not having it back! 😝 I have just had a look at the schematic for the gun in the forum's library, it's a system that I'm not too familiar with tbh. Initially I thought that it might be the CO2 transfer port but it looks like the PPK doesn't have one as it has a permanent and direct connection to the CO2 capsule but it does sound like the CO2 is being starved from the system somewhere. I'd go back to your original idea of adding some packing under the hammer, at least that way it'll either work or won't but either way you're be nearer to tracking down the 'culprit' that's responsible. If that fails then the CO2 bottleneck has to be somewhere between the capsule and the valve, I'm guessing ! Slide interference could be possible too, if it's lifting or twisting that could be making it hang or at least resist against something. Keep us all informed please buddy, this is a bit of a head scratcher....
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Modski66
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Post by Modski66 on May 16, 2023 10:58:04 GMT
Tried the hammer spring packing, but it made it worse. But I have a cunning plan!
I took the blowback unit out to try it in-situ on the frame, there does seem to be various places in the travel that cause tiny little snags, like going over the trigger bar to push it down, and obviously re-cocking the hammer. The plan is to clean, polish and smooth every contacting surface to remove any wasted energy from the blowback function.
Got to get back to work now though... 😕
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twodoctors
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Post by twodoctors on May 16, 2023 15:35:14 GMT
Sounds like that same as my PPK. I think it is a bent frame issue...
...you can borrow mine and swap parts and see if you can make a working gun out of it.
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Modski66
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Post by Modski66 on May 17, 2023 14:58:52 GMT
Some progress... Noticed a bit of resistance in this area: So that has been smoothed off, also the base of the blowback unit was a bit rough and quite a sharp corner for the slide to drive it over the base of the hammer to recock it. I have smoothed that out too, but I think I need more radius on it, plus the lower part of the hammer face needs to be smoothed out and polished. More to follow.
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Modski66
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Post by Modski66 on May 17, 2023 16:42:40 GMT
None of the above seem to have had the desired effect, I even took the edges off the the hammer spring guide to reduce resistance. It has improved a bit though, but it's puzzling that the fps can vary, but not affect the blowback operation. The fps can be over 200 with steel bb's and not cycle, but can be as low as 175 and successfully cock the hammer. Tried various bb's; Blasters were 360fps but the behaviour was the same, I tried Gamo lead to see if a tighter ammo to barrel fit would give a bit more pressure to the blowback unit, but no good. There is a YouTube video of a guy dropping Gamo bb's down the PPK barrel, but on other bb pistol barrels, they would not go down, his suggestion was that the 'sloppy' barrel was a cause for low power and inaccuracy. I have got a spare brass barrel that is actually tighter, so I might give this a try.
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Post by HeadHunter on May 17, 2023 18:09:32 GMT
Now I don't know anything about the PPK's valve and how it works but on a standard auto replica there's a rocket nozzle inside the valve that is pushed back by a BB as it's loaded into the breech, once you pull the trigger the CO2 goes to the path of least resistance and shoots the BB down the barrel which at the same time closes the rocket nozzle and redirects the CO2 to go into recoil. I'm guessing that there must be a similar system incorporated into the PPK (trigger pulled, CO2 released, projectile fired, CO2 redirected into the blowback unit, slide returns into battery and feeds another BB into breech), which leads me to think that the error is in the valve unit at the crossover point between firing a BB and activating the blowback, it's either activating early (giving you reduced FPS and good blowback) or activating late (resulting in a high FPS which essentially starves the blowback unit of the necessary CO2 needed to accomplish the task).
It's funny how the fault is completely random with the FPS versus blowback, seems to be no consistency in the error (don't you just hate that).
As I said I really don't know how the PPK valve works, so I'd be interested to hear an explanation from you.
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Post by flatrajectory on May 17, 2023 19:34:03 GMT
Mark.....is the piercing pin clear and unobstructed. ? Pete,
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Modski66
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Post by Modski66 on May 17, 2023 20:17:20 GMT
Mark.....is the piercing pin clear and unobstructed. ? Pete, Yes, very! Drilled it out to 1mm, straight through the sintered filter as well to make sure there is no restriction. I do have a spare... 😉 Just been trying the tighter barrel, possibly made the re-cocking problem a bit worse! I left the 'new' one at its original length of around 5.5 inches, got over 405fps with the Blasters 😁 but accuracy was pants 😭. When it blows back, the barrel pitched downward, so everything was hitting lower, presumably the lock-time had increased enough to have an effect. 🤔 I know on the other side of the pond some people have converted them to fire repeatedly with one pull of the trigger, 😱 I can't get past about eight shots when taken steadily. More head scratching required.
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Modski66
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Post by Modski66 on May 17, 2023 20:55:59 GMT
It's like the gas to the BBU is being wasted somewhere; studied the schematic, but can't see that anything like a seal or clip or something is missing that would affect operation.
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Post by HeadHunter on May 18, 2023 7:47:52 GMT
Does the stick mag direct feed the BBs into the breech, like the pellet firing double action autos do ? (making it effectively the breech) If so it could be a bad seal between mag and valve. I still think that it has something to do with the shut off valve for firing the BBs that then redirects the CO2 to the BBU as the gun cannot do both at the same time, CO2 (like water) will always go down the path of least resistance, so there has to be some sort of shut off valve after it's fired the BB down the barrel otherwise the CO2 would all escape down the barrel and not be redirected to the BBU. If the shutoff valve is working fine then the FPS would be very consistent, gradually reducing over time (as per normal CO2 consumption), if the FPS results are erratic then it's safe to assume that either the shutoff valve is either not opening fully and thereby closing early (low FPS) or opening fully and closing normally (resulting in a higher FPS). But either of those two statements are based on a standard auto replica BBU and not on the PPK, I'm guessing that the hammer fall on the PPK actually directly activates the valve in the BBU, which (if that's the case) makes my previous paragraph just bollox really, lol. But either way, the PPK needs to have a system that incorporates a shutoff from the barrel and redirects to the BBU. I had a faulty valve in my Python a few years back, it wouldn't seal properly after a couple of shots and kept pissing CO2 out of the rear of the unit (under the hammer), I checked everything, it all looked good BUT it turned out to be a hairline crack in the valve stem between the ports that once it got cold (from the CO2) it caused it to fail. To have successfully diagnosed this from the onset of the problem I would have had to have performed a NDT using magnetic flux paint, a magnet and a magnifying glass ! I ended up swapping the whole valve out as you can't get hold of just the valve stem, swapped the valve stems and viola ! The fault was finally found and on close examination (a magnifying glass) I finally found the miniature crack between the ports that caused the issue. So why am I stating all of this ? Well twodoctors has kindly offered you his (non-working) PPK, it might be a good idea to swap out parts between the two just to diagnose the problem with your gun, you might just find that the fault is on the micro scale rather than the macro, just a thought buddy.
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twodoctors
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Post by twodoctors on May 18, 2023 8:00:01 GMT
Mine is working but have the same slide problem. Let me know if you want to utilise it Modski66
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