Shu Wei Firing Problem

Hello. As you all know I'm pretty new to this model gun business. I have recently modded my Shu Wei to fire off Hwa Shan disposable rounds by enlarging the barrel, via file, by a little in order to let the rounds chamber more easily. However, out of 50 Wha Shan disposables I was only able to get about 19 of them to fire properly (and not in succession). I then tried out the KANECAP 7mm caps with the Marushin M9 type cartridges that came with the gun. Again, out of 50 or so caps, I only got a handful to fire. But the caps seems to fire more often than the disposables.

Anyways, every time the KANECAPs didn't fire, I checked out the cap and it always had a pretty deep indent indicating that yes, the rear firing pin did get to the cap. For the disposables, Im not so sure.

Every time it fired, the weapons cycles perfectly (re-chambers a new round if there is round in magazine, or holds the slide back when empty). However, the most I got this thing to fire in succession was 2 rounds and that was a one time thing only!

I just wanted to know, is it my gun's problem or is the the caps? Mind you, it is pretty humid here in Taiwan. Maybe I'm not storing these caps properly?

If someone could help me out with this, that would be awesome!
Ill post some pics of the caps and barrel mod soon

Hi picure,

It isn't uncommon to find faulty caps in some boxes. Many of us have experienced several misfires and traced the problem back to faulty caps
High humidity could well make your problem worse. If your caps are getting even slightly damp they'll not ignite properly.
Keep your caps in their boxes, stored in an airtight box with some silica gel packs to absorb any moisture.

The WaShan disposable cartridges aren't without problems either. The cartridges have white plastic "primer" and endcaps which can stick to the outer casing of the cartridge.
These can stick quite firmly enough to stop the hammer's action forcing the internal firing pin into the cap.
With care, it's possible to gently push the white plastic endcap into the cartridge a small amount and apply a very small amount of silicone oil just to lubricate it a little.
Very carefully push the primer into the cartridge too, again applying a very small amount of silicone oil. If you push to hard, there's a danger of igniting the cap, so be careful
This will break the seal enough to let you push the primer back flush with the bottom of the case.
That should allow the disposable cartridge to function and ignite when the hammer falls.

I had similar problems with some boxes of 5mm caps, see here:
https://mp40modelguns.forumotion.net/modelgun-caps-cartridges-and-magazines-f6/weak-caps-t353.htm

Thanks for the reply. I also wanted to know, is there any way of telling good caps from bad caps? Because I wanna be able to fire off 15 rounds in succession. Im sick of em duds!

It can be difficult to tell which are duds unfortunately. The obvious signs are if the charge falls away from the plastic cap body, any obvious signs of wetness on the charge, getting the caps wet with silicone oil during loading... that type of thing.

It does sound like the high humidity you're living in might play a part in your problem unless you've been really unlucky and bought a box with several duds in it.

I've just seen the video of your M9 Beretta firing the single cartridge.

I believe that all the caps used in PFC cartridges are made by Kane Company but I wonder which ones you have used

The most common types used are Marushin and M.G. Caps



A product called Real Flame caps were (are) made by Kane too

which do you use

The kind of KANECAP I use are the ones distributed by Wha Shan in the pink boxes. They are also "REAL FLAME" shots "FOR AUTOMATIC & REVOLVER"

Searching through the Internet's pages I found these

Kane caps, are these the ones you use

I'm not familiar with these so can't honestly comment on what they're like. If you are having constant problems with them that can't be cured by storage in dry containers all I can suggest is that you try Marushin or MG Caps.

You are dead on with the picture. Those are the kind Im using. But this is my first box that I am going through. Im thinking of buying another box to try and see if I just got a bad batch. The problem with buying caps from other manufactures is that its almost impossible to get model gun related stuff here in Taiwan. It seems like that KANECAPS are the only kind of caps distributed in Taiwan for the meanwhile.

I feel for you - the first batch of caps, and such a bad one... I was also frustrated when I hit bad caps in the past.

Trying another box from different batch/import/seller might help you to check what's going on. I hope others might be better.

Are you permitted to import caps into Taiwan If you are, I'd suggest you order from Francky or shazhib in Tokyo.
Francky's at www.franckys-modelgun.com
Shazhib by PM through the forum.

Trying another box sounds like a good idea, batches of faulty caps aren't unheard of. The next box might be perfect

My only other suggestion at the moment, is to double check that your cartridges are clean and loaded correctly.
Assuming that your M9 uses cartridges similar to this:

I've "borrowed" smootik's photo from his M84 Beretta review. The inside surface of the cartridge must be spotlessly clean and clear of all deposits and residue left behind after previous firing sessions.
Friction is possibly the Modelgun's worst enemy. Cartridge internals must move freely and smoothly to operate and cycle the gun correctly.
The rubber O-ring you can see here arund the Primer / firing pin has to be clean and intact. Any cuts or damage to this O-ring will cause loss of blowback pressure.

After making sure everything's clean, dry and intact, try loading like this:

Put the washer into the casing first. If the washer is slightly dished on one face, put it into the casing so the dished side faces the tip of the "bullet"
Next, smear a very thin film of Silicone grease around the edge of the cap, put this into the casing with the powder charge facing you,
Push the cap into the casing with the widest end of the loading tool. The cap does not have to be pushed all the way down the casing.
Smear a very thin film of Silicone grease onto the primer / firing pin's O-ring, and place it into the cartridge base making sure the primer is in far enough to sit flush with the base
Screw the base onto the cartridge

This method should make sure there's no moisture from oil contaminating the cap and that the grease applied will make sure the cap blows back smoothly after it fires. All the gas pressure will remain in the cartridge too

As I've mentioned before, the WaShan M9 Dolphin usually fires very, very well. We'll have yours firing like it should soon

Thanks Cerwyn, I actually just checked out yhaoo bids in Taiwan and found a seller here who sells MGC 7mm caps. Im going to try those next once I'm through with these damn KANECAPS.

I just tried your method and again, got a misfire. Same result, firing pin mark deep in the cap with no bang. Does oiling the parts within the cartridge prevent misfires, or does it just help the cycling better? Is it really bad caps that I have thats causing all these misfires?

I also tried oiling the Wha Shan disposables to the point where I can push the white primers in by my finger and I still get constant misfires. Sometimes if I pull the trigger enough times it will go off. Sometimes I pull the trigger multiple times and it does nothing.

MG Caps should be OK. Generally they work reliably but if they get wet with water moisture or oil they'll not ignite.
My own experiences with them would be 99.5% reliable ignition, seldom do I suffer misfires but they do happen.

Too much oil inside the cartridge could well get the powder charge wet and cause misfires.

The internals do need some lubrication otherwise they won't slide smoothly once the cap goes off.
A little oil in the cartridge also produces extra smoke effect

If your attempts at firing leave deep indents in the powder charge it sounds like the hammer - firing pin - cartridge primer/firing pin - barrel detonator pin sequence is working.

It sounds more and more like you have a bad box of caps there.

One problem I know of with WaShan Beretta M9 is that the Detonator Pin cast into the barrel has a hardened tip fixed to it. This has been known to come off making the detonator pin shorter.
This will stop the modelgun firing completely though.
The dents in your caps suggest all should be well but it might be worth checking the Det.Pin is intact.

Another possibility might be the hammer spring isn't allowing the hammer to drop hard and fast enough onto the firing pin.
I've heard of this happening on different models but don't know enough to comment on how to check it and fix it.
Hopefully one of the other guys can...

Thanks alot Cerwyn! Thanks for the help!

Just a question. If there is a positive indent in the cap but no fire, is that a 100% sure chance that the cap is bad or could it be a weak hammer spring? Just exactly how much force do you need to fire a cap?

The best way to learn that would be experimenting with caps - in safe conditions!

When I hit bad caps I tried detonating them manually.

Wear protective glasses. You only have two eyes.
Put upside down a metal lid with raised edges. This protects floor (or sink) from heat and particles launched when cap explodes.
Cap goes inside, charge facing upwards. You can try glueing cap to the lid, because I found that sometimes caps just flew around.
I had a long (30-50cm), thin (<1cm), flat piece of wood. Put a nail through it, to simulate firing pin. You can vary shape of nail end, striking with pointy end, or with head end. Long piece makes you far enough from cap effects, thin allows easier inserting of nail, flat partiall protects heat from going upwards. Make sure nail is kept strong in the wood - otherwise cap will make it fly away!!!
Now hold one side of "detonator", position the other side with nail over the cap. Get a fairly light hammer with a long handle (about same as length of "detonator" wood, knock from above on the other side of nail that goes through wood. Bottom of the nail shoud strike cap and detonate it.

BEWARE! wear safety glasses, and remember that a single cap can blowback a heavy metal modelgun bolt/slide!

What I discovered was that speed of strike and shape of nail do matter. Bad caps that were already crushed usually did not detonate at all, or detonated only after strong hit. Normal caps detonate on much lighter hits. I also had impression that pointy end caused more detonations than a rounded end, but for bad caps larger surface seem necessary. Speed was also a factor, strikes needed to be fairly fast to work.

It would be probably better to built a device that could use repeatable force... hmmm, Lego NXT kit protected by "blast skirt" dropping weight from a preset height...

Conclusion? Not really conclusive, but enough evidence that a bad box of caps was really bad box of caps, either requiring more force to detonate or not working at all. Fresh caps detonated easily. If you have a "middle" quality caps and modelgun strikes lightly (or slow), this could be a reason for less reliable action, but not as bad as you described, or I had with my Skorpion.
In case of bad caps force needed to be seemingly stronger than what is usually available in pistol.

It's a good idea to check if hammer falls easily (can be probably checked with slide off if you are careful). By moving pin manually you will also see if it is sticky, or moves badly.

Thanks for the advice! I just got a couple of MGC caps and got my Beretta 92FS to fire 5 caps, reloading each time since I only have one cartridge at the time to try it on. However if I release the slide on the round, the ammo slam fires which means by the time I get more cartridges, it will fire on full auto after the first round. Any tricks to prevent this from firing? I have read somewhere else on this forum that moving the detonator pin could help but the detonator pin on the Shu Wei Beretta is fixed, non-removable/adjustable.

Thanks!

Hi picure,

It does sound like your new box of caps are firing this time, you'll need to make sure you keep these sealed in an airtight container to keep them dry.
As you've mentioned before, humidity is a problem where you are so maybe silica gel bags might help absorb any moisture in the air.

I managed, with some dificulty today, to measure the length of the Detontor Pin fixed in my WaShan Beretta's barrel.
Pin length works out at 13.66mm nominal.
Being fixed, these pins are not removable, nor adjustable, but they do have a hardened tip fixed to the end.
It's known for this tip to fall off, thus shortening the pin. Result of that is the model won't fire at all.
As yours is slam firing just by closing the slide, the pin should be intact, but just make sure the tip isn't working it's way off the pin.
It could, arguably, make the pin slightly longer which is causing the slam firing.

Recoil spring free length in my particular WaShan M9 is 144.28mm

Another possibility could be the gun's firing pin which is spring loaded and located inside the firing block in the slide. Make sure that's moving freely and easily. You can cock the hammer and looking at the firing pin from the rear of the gun, the hammer strikes a short, top hat shaped pin (part #27) located in a drum (part #5) that turns with the safety switch. ***Note the drawing is of WaShan's Beretta but the parts indicated are identical to the Marushin. Note also the Detonator Pin shown here is removable***
If all is well, the pin will move a short distance inwards, then spring back again when you stop pushing.



Turning the Safety switch to "Safe" disengages the short pin from the main one in the firing block. If, possibly, the safety switch has moved just enough during the drop to turn the drum, perhaps the two pins have jammed together.
This may account for any stiff movement and the fact the gun fires as soon as the slide travels forward
Forum member trevinator has been having problems with his Marushin M9 Dolphins, similar to yours in some respects:

Ref: https://mp40modelguns.forumotion.net/modelgun-problems-f5/marushin-m9-dolphin-firing-problems-t2548.htm

If your Detonator Pin is the correct length and the Firing pin moving freely, double check your cartridge loading. If you've only one cartridge, and you fired 5 caps one after the other in quick succession, it could be something as simple as a build up of dirt and residue in the cartridge causing friction or not allowing the internal parts to get into correct positon.
Maybe there's dirt stopping the washer and plastic cap entering far enough into the cartridge. If the cap's stuck and too close to the cartridge's firing pin, it might be being struck early and firing.

As a rough rule, you can probably re-load a cartridge immediately after firing twice, before dirt builds up too much. Wipe the inside of the cartridge with a Cotton Wool Tipped Bud, (Q-Tip) before reloading.
Better to wash and dry the cartridges thoroughly after every firing really for best results. You would do well to buy yourself a box of 15 at least for maximum enjoyment

WaShan Recoil Spring Dimensions:-

All taken from the spring in my own model.

Outside Diameter 9.83mm
Inside Diameter 7.85mm
Wire Thickness 0.64mm (0.025")
Spring Free Length 144.28mm

Thanks for the reply man. But I have finally found the problem to the gun.

It turns out that my slide was too far forward when in the "slide closed" position. Some people refer this to the slide not being in "battery" which means the slide is not in the proper position during firing. This leads to the hammer not striking the firing pin directly on top which results in short firing pin movement. In this case the firing pin is too far away from the hammer strike point.


Slide too far forward, "Out of battery", rear sight end view.


Slide too far forward, "Out of battery", muzzle end view. (note: guide rod is not visible)


The slide "in battery" rear sight end view.


The slide "in battery" muzzle end view (note: guide rod is now visible)

I was able to fix this problem by adding 3 plastic rods, cut from a Q-tip, inside the spring of the locking block.
This prevented the locking block from sinking too far under the barrel which results in the slide resting too far forward.
I think this was a design flaw by Shu Wei but it was a cheap and easy fix. After the fix, my Beretta was able to fire off the rest of the Wha Shan disposables and the Kane Caps, even though a few of the kanecaps and disposables took a few more pulls of the trigger than the MGC caps. And this is because the firing pin can now reach the cap easier. Since I now know what the problem was, I think I will continue to use Kanecaps and Wha Shan disposables because they are way louder than the MGC caps.

Here are the pics of my fix.


Plastic insert in the locking block.



Plastic insert in the locking block.

This however still does not solve the slam fire problem however it does help it some. I still get slam fires with the MGC caps but not with the Kanecaps. It turns out that the Kanecaps requires more force to fire therefore releasing the slide on a Kanecap does not ignite it.

That's great news, nothing more pleasing than learning a problem has been fixed, and a clever fix that is too!

I had time to fire my WaShan M9 yesterday, using MG caps in MGC reusable P220 cartridges. These MGs are loud enough
to have my ears ringing indoors, I'd like to hear the Kanecaps if you reckon they're far louder.
A bit more volume wouldn't go amiss in some of my other models, maybe Kanecaps could provide the answer.

Maybe you could video your Beretta firing a mag'full of these Kanes for us to enjoy please

None of the usual outlets we use seem to list this particular Kanecap however!