Beeman 2004 (P17) .177 pistol

[glam69]

Please could anyone offer any advice on why my Beeman 2004 keeps getting jammed? The pistol cocks ok ie the pressure does build up when pumped and I cannot hear any escaping air, but when the trigger is pulled the pistol goes through the motions of firing, but the pellet doesn’t move and has to be removed with a rod.

How critical is the breech seal as that seems a little worn, also can the barrel move to widen the interference fit between the barrel end and the breech seal?

Additionally does anyone know the seal sizes?

Thanks for taking time to read and thank you if you can help.

[Halimede]

If a P17 is the same as an Alecto then, yes the barrel can move. I say that because mine is clamped in place with a sort of cross strap and there appears to be about 4mm between either side of the clamp and the shoulders on the barrel. The fore-end of the barrel doesn't look to be up against a shoulder.

[Halimede]

A further thought. The breech seal is easy to damage with a badly seated pellet but I never had mine so bad that the pellet doesn't move. My Alecto has a hole up through the top of the body by the rear sight. Perhaps you could try draping a tissue over the rear of the gun and see if it moves on firing.

[TonyL]

Off the top of my head, isn't the 2004 / P17 the HW40 clone?

Worth checking the bits already mentioned.

I don't have the time right now to search out the posts and share the link, but I seem to remember there being a very detailed thread on the Pyramydairblog about stripping and improving the P17 / 2004 as well as a comparison to the '40. There may well be seal sizes there too.

Maybe I'm dreaming but I think I can remember a post by Todd Cooper on the HW40, too, which will have been very detailed.

Hope this helps.

[Halimede]

I agree that a 2004 looks like the HW40. I mentioned the Alecto because from what I can see from peoples pictures, the barrel mounting looks the same. I can't say that it will move, but it looks like it might so I suggest checking that it hasn't.

[glam69]

As the pistol is only 6 weeks old the seller has kindly told me to return the pistol and he will supply a new replacement.

The seals for this pistol are as follows:-
BS006 Valve stem tip
BS008 Valve plug
BS009 Breech
BS117 Piston ( tighter fit than the original 2.5mm x 20mm)

Regards,
Gary

[Schwinnsta]

This could not be the breech seal. It is likely involved with the valve or the linkage from the valve to the trigger. It is time for a tear down.

[glam69]

It was the valve pin that had moved which caused the problem of not firing. Punching the pin back to the correct position and re-tightening the set screw solved the problem.

[Modski66]

That's great to follow up with your solution, I could well help someone else down the line.