Combro and CO2 pistols

[Aimstraight]

Hi,
If anyone knows of a good stripping guide to CP88 I'd be grateful for a pointer...
A.G

Not sure of a full guide, but there are a few threads on here regarding removing the slide. That was related to folk having problems opening or closing the slide. That is most often due to lack of lubrication on two pop up plates that lock the slide closed. It may be worth you removing the slide to see what is going on (i.e. are the rear vertical faces of the plates worn such that the slide does not stay fully closed). Think you are right in saying that there is potential for play in the mechanism that holds the slide closed and therefore the mag onto the barrel o-ring and gas nozzle.

If you want to remove the slide PM me and I will dig out one of the old threads.

[harvey_s]

Hi Harvey,

I was using RWS Target CO2, they are flat heads I believe.

Regards,

A.G

They are, which only leaves the sensors being too close to the muzzle, spacing it further away would probably cure it - but also increases the risk of a pellet strike unless things are lined up extremely well.
This is about the only drawback of the combro unit.

[lensman57]

Not sure of a full guide, but there are a few threads on here regarding removing the slide. That was related to folk having problems opening or closing the slide. That is most often due to lack of lubrication on two pop up plates that lock the slide closed. It may be worth you removing the slide to see what is going on (i.e. are the rear vertical faces of the plates worn such that the slide does not stay fully closed). Think you are right in saying that there is potential for play in the mechanism that holds the slide closed and therefore the mag onto the barrel o-ring and gas nozzle.

If you want to remove the slide PM me and I will dig out one of the old threads.

Thank you for your help. I have actually removed the slide a few times and there doesn't seem to be any problem with the locking tabs. The release works as it should. The problem of the play in the slide that will also move the barrel and affect accuracy and MV is another matter. I read somewhere that the cure is to put the slide in a vice and very gently bring the two sides closer. This is not something that I would like to try with brittle cast Aluminium. There is supposed to be guide on UBC or something like that I believe that may help me strip the gun and examine the two likely candidates for the gas leaking. The spring loaded brass nozzle and the O ring on the barrel. Both of these suppose to seal the magazine and direct the CO2 on to the back of the pellet and into the nozzle.

Regards,

A.G

[Aimstraight]

Some info how to remove the CP88 slide here.

Edit: Our posts crossed. Yes try the UBC, can not remember whether the search works without being logged in.

[lensman57]

They are, which only leaves the sensors being too close to the muzzle, spacing it further away would probably cure it - but also increases the risk of a pellet strike unless things are lined up extremely well.
This is about the only drawback of the combro unit.

Well, your post turned out to be prophetic. While trying to test the HW98 after some minor modding the bloody unit slipped and the pellet put an end to its troubled life. Combro is no more. Now I will have to source one out tomorrow.

Regards,

A.G

[harvey_s]

The best thing about combros is they can be repaired cheaply unless you've REALLY mullered it...

[lensman57]

The best thing about combros is they can be repaired cheaply unless you've REALLY mullered it...

I think that this one has had it, the pellet caught a part of the main board and also cut some contacts.

A.G

[Robet]

Bought a silencer recently for my CP88 so as per my prior post got round to trying the combro on the silencer attached with insulating tape.

Using RWS Hobbys

Worked a treat, over 8 shots the FPS was 390 avg, 377 low, 411 high & PDS 2.37 2.21, 2.63

Rgds, Rob

[lensman57]

Bought a silencer recently for my CP88 so as per my prior post got round to trying the combro on the silencer attached with insulating tape.

Using RWS Hobbys

Worked a treat, over 8 shots the FPS was 390 avg, 377 low, 411 high & PDS 2.37 2.21, 2.63

Rgds, Rob

Hi Rob,

Which adapter are you using to connect the silencer. The one that I have bought leaves a lot to be desired.


Regards,

A.G

[Robet]

Hi Rob,

Which adapter are you using to connect the silencer. The one that I have bought leaves a lot to be desired.


Regards,

A.G

Funny that, so does the 1 I bought. "leaves a lot to be desired" is being kind.

It had a number of problems including a crappy silver screw that was too long & the screwdriver slot was offset. So replaced that.

The scallop that was supposed to fit over the bulge on the muzzle didn't, so had to be adjusted with the dremel.

Once the adapter was fitting flat & tightened, the silencer was being clipped 'cos the flat bit of the adapter was different thickness from one end to the other so tilting the silencer.

Straightened that up with shims.

Yes I did complain to the seller after who gave me a 50% refund. I should have sent it back but I couldn't be bothered & I didn't believe a replacement would have been any better.

Very disappointing as the ad says "High quality 1/2" UNF male threaded adaptor - suits most popular silencers. Made for us by a leading UK manufacturer to the highest standards"

No wonder our engineering industry has disappeared if that's an example of "highest standards".

Unfortunately all the ads I've seen say the same thing so they're probably all from the same source.

Might try to find a proper 1 made in Germany.

Rgds, Rob

[lensman57]

Funny that, so does the 1 I bought. "leaves a lot to be desired" is being kind.

It had a number of problems including a crappy silver screw that was too long & the screwdriver slot was offset. So replaced that.

The scallop that was supposed to fit over the bulge on the muzzle didn't, so had to be adjusted with the dremel.

Once the adapter was fitting flat & tightened, the silencer was being clipped 'cos the flat bit of the adapter was different thickness from one end to the other so tilting the silencer.

Straightened that up with shims.

Yes I did complain to the seller after who gave me a 50% refund. I should have sent it back but I couldn't be bothered & I didn't believe a replacement would have been any better.

Very disappointing as the ad says "High quality 1/2" UNF male threaded adaptor - suits most popular silencers. Made for us by a leading UK manufacturer to the highest standards"

No wonder our engineering industry has disappeared if that's an example of "highest standards".

Unfortunately all the ads I've seen say the same thing so they're probably all from the same source.

Might try to find a proper 1 made in Germany.

Rgds, Rob

Hi Rob,

Exactly the same here. The bit that was supposed to fit in the barrel end was so oversized that I had to machine it to size. The groove for the scallop was not large nor deep enough to sit firm but flush with the end of the barrel and was remachined. The screw is a joke and works itself loose. Once secure the adapter body is not flush with the end of the gun and that " genius of a design slide spring " pulls the barrel forward and tilts the adapter so I had to make a brass shim to fill the gap. After all the machining I would have been better off making one from scratch myself. It also like yours clipped the inside washer of my Weirauch silencer as the adapter even though screwed home will loosen and tilts even further after a few shots. I even made a small 3.5" silencer for it ( as a prototype ) so it wouldn't tilt because of the weight of the weirauch. It has worked so far but I am not a happy chappy with this gun. I am also scratching my head as how to make the barrel, magazine and the CO2 spring loaded nozzle come into contact together and make for consistent shooting. As it is there is so much waste of CO2 that I get only about 3 or 4 mags before the pellet rolls off the end of the barrel, way short of the 60 shots claimed in the reviews. Where do they get their guns from I wonder.


Regards,

A.G

PS: I have also found another design fault with this gun. The hammer is made of cast Aluminium and it hits a hardened sprung pin that I presume activates the valve. I have only fired about 300 or so pellet through this gun but the Soft Hammer has already been dented by the hardened steel pin. This means that the firing pin is not pushed home fully on release of the trigger and in time the gun will become even weaker if that is possible ofcourse. This is not German engineering as I would expect it. I could machine and harden a piece of silver steel and insert and Loctite it in the hammer but I have to take the gun apart to release the hammer. We are not Amused.

[robinghewitt]

Thanks for the trick but I just tried it, three times and it gave a reading of 1068 ft/s. Such a powerful gun. Maybe they sold me the real stuff.

1068 is a magic number with cb-625. Push a pencil in from the front and when it reaches the first optic you will get 1068 ft/s

You have a sick chrono, either damaged optics or a problem in the battery stack.

[robinghewitt]

I think that this one has had it, the pellet caught a part of the main board and also cut some contacts.

Poor thing, what did she do to deserve that?

However it is a fixed price repair, for £7.50 I will patch it up and get it through the calibration test

The test is 3 consecutive shots at 500 ft/s all within 2 ft/s of the test gun and a consistency of better than 1 ft/s

While I am here it is much easier to make a cb-625 read slow with muzzle blast than it is to make it read fast. If you see fast, look elsewhere for the problem,

[Robet]

Didn't think I'd be the only one with a dodgy adapter.

I'm keeping an eye on the adapter screw as well, particularly as I had to replace it out of my spares box.

However, now it's working I don't seem to have the same kind of problems with the gun itself. I've only had it a few weeks but the slide seems fairly OK, only slightly sloppy & my groups are OK at 10m.

My silencer is about 6" but is very light as it's made of plastic stuff, Delrin I think.

I'm getting about 10 mags per CO2, I'm using Umarex cartridges.

There is a bit of wear on the hammer but I'm still getting good power I think, see post above.

Oh & my gun is 2nd hand & it's a glossy one from 1998 as far as I can tell. Unfortunately sounds like you might have a duff one.

Rgds, Rob

[lensman57]

1068 is a magic number with cb-625. Push a pencil in from the front and when it reaches the first optic you will get 1068 ft/s

You have a sick chrono, either damaged optics or a problem in the battery stack.

The 1068 one has been laid to rest due to being shot up.

A.G