PPK /s conundrum

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.

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! 😝

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... 😕

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.

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.

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.

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.