New to Model Guns Please Help Me Out

the caps did not come from the gun .. well not true they where in the box but they gave me two boxes of mg caps and that cap strip of red caps.. they where in the box i bought however they had two suzukis and only one had the red caps.. its not part of the kit though i have found.. they were to revolver cap guns.. the kind that the caps go on the end of the bullet.. but i was just tinkering.. i may make a new det pin at this point.. i just dont see why.. kinda pissed really lol.. like i said if i whip the gun in my hand and pull trigger it does fire and puncture the cap.. but when stationary it just recoils no noise.. showing my pics of slide what do i have? side fire or center? also where do i get these roaring washers?

you know looking at your pic my caps look like your top caps.. but more of a round indent pushing through.. now looking at your gun im wondering if mine is working right.. i still dont see why it would as its still silent.. i may end up machining a new pin and getting those washers..

whats the thickness of the roaring plug and the normal plug?

dont mean to keep flooding this thread .. but.. i have some info i wanna show and need help..

this is what my det pin is like in this gun.. is this the same for other people?





should it come out farther then the washer? i can throw my det pin on my home lathe and take away some cone shape to make the thin pin longer..

Cerwyn wrote:

Don't worry about flooding the thread weno! We'll keep this going until we get your Suzuki Beretta firing properly   

To answer your question why your model is so silent when it fires first, bear in mind the cap performs 3 tasks inside the cartridge.

3: When the cap is punctured, noise and smoke escapes out of the cartridge nose and out of the barrel and ejection port

If the cap isn't punctured then very little sound or smoke will be created.

If your fired caps look like the top two in my photo, John's suggestion that the firing pins in the cartridges may be slightly short is definately worth checking out.
The pins must be long enough to strike the charge hard enough to ignite and cycle the gun, but not quite long enough to puncture the cap.
Similarly, the hole in the dished washer may be a fraction small not allowing the cap to puncture and blow through.

This is stuff i need to know.. once i modify a washer or anything there is no going back.. my pins on bullets are pretty much all equal.. i cant make them longer.. they vary between .15mm - .01mm so i cant make them longer.. i was thinking about modifying the chamfer on my det pin so the tip comes out of it more.. i have some acrylic rod here i may make a det pin out of it and test things out.. as for washer i would make it less thicker if need be.. but i really only wanna mess one bullet up.. so knowing the variables on the det pin and washer would help me make a decision..

any update on pics? can you give me pic of det pin in the washer? and thickness of roaring washer and a pic of normal washer next to roaring for height differences

weno wrote:

First Gun i have is a "Suzuki Beretta M92 SB".. what i dont understand is if i am loading my bullets correctly or if my caps are junk..

Fingers crossed for getting this one sorted out :-)
Models are often frustrating, but give you that nice feeling when you somehow figure out what was needed to make one work better.

Suzuki was the first company to release Beretta M92SB model, followed by MGC and Marushin. Suzuki model featured very realistic (compared to other modelguns of the time) mechanism

One troubleshooting idea is to put plasticine (soft modelling clay) inside cartridge. You could use a spent cap, fill it (to the rim) with clay, and install in the model. After firing and careful disassembly, pin impression in clay should give an idea on what is missing.
My ideas are pretty much what has already been mentioned:
- caps: bad batch that doesn't want to behave (clay test should show if they are hit with enough force).
- detonator pin in barrel: too short, deformed after use (shorter or interfering with cartridge top), seated too deep (could happen after use if deformed).
- firing pin in cartridge: broken (if in single cartridge), too short (unlikely, unless wrong type of cartridges are used), rusted (rust and its removal could make this pin shorter).
- chamber: dirt or deformation may prevent cartridge from moving forward freely when struck.
- striking bar/hammer: friction, interference, or weakened spring may prevent bar from pushing cartridge forward enough.

Quote :

Second gun is a MGC Beretta 1934 .. I would like to find proper Bullets and caps for this gun.

You might have seen my review of this model:
https://mp40modelguns.forumotion.net/t2657-mgc-rmi-beretta-1934-metal
It has been modified from original to fire Marushin blowback cartridges (not by me). Modification to the cartridge is described in the review, but I don't know if there was modification of detonator pin in the barrel.
M1934 was very popular among modelgun makers. After the initial non-blowback (cap in tip) version in late 1960s, MGC manufactured a blowback version in 1970s, just before metal modelguns were effectively banned. Western Arms took over and made ABS model, but that's different. It would take some searching and asking around to find cartridges though, as MGC model was not reproduced since 1970s.

weno wrote:

I just looked at it.. You said it was modified but i dont understand what was modified..

I don't know exactly what was modified, as it wasn't done by me, and I don't have a non-modified model for comparison. Usually parts that need modification are cartrdige (as described) and detonator pin in the barrel (length adjusted or tip reshaped for new cartridge type).

My guess would be to:
a) find original MGC cartridges
b) modify Marushin M84 cartridges (start with one) and see if they would work with pin already in the barrel.

Your model seems to look just like mine (although it's hard to compare pins - can't see it at all in chamber on your photo), so I would probably start by getting a Marushin M84 cartridge (more available outside Japan) and fitting it to your model. Original MGC cartridges could probably be found in Japan, through one of forum members (Shazhib).

smootik wrote:

My guess would be to:
a) find original MGC cartridges
b) modify Marushin M84 cartridges (start with one) and see if they would work with pin already in the barrel.

Your model seems to look just like mine (although it's hard to compare pins - can't see it at all in chamber on your photo), so I would probably start by getting a Marushin M84 cartridge (more available outside Japan) and fitting it to your model. Original MGC cartridges could probably be found in Japan, through one of forum members (Shazhib).

Can someone point me to M84 Carts?

Cerwyn wrote:

Try Forum member kharris for M84 carts. You'll also find him trading as "Model Gun Collector USA" on Gunbroker.com

Here's Brand new, unworn, Marushin MP40 Detonator Pin sitting in it's cartridge recessed washer. It doesn't protrude by any appreciable amount:

 

This is a "Roaring Plug", side fire type alongside a standard Marushin cartridge washer:

The standard washer is 2.75mm thick, the Roaring Plug 3.75mm thick

well my det pin is flush with standard washer.. what does your det pin look like on the standard washer? im confused now how the roaring washer is thinner and still the pin doesnt stick out alot on that washer.. so im not sure what i should do.. will kharris have these roaring plugs to so i can buy everything from one guy?

Cerwyn wrote:

Please look at it again, the photo shows the Pin in the standard washer.

Also, the Roaring Plug is thicker than standard, as shown in the photo.

if the roaring washer is the "thicker" one then thats exactly what my bullets came with.. no need to buy them then.. they came stock on my gun.. i thought the roaring washer was the thinner one with the bigger convex shape in the bullet end.. so it looks like i dont need a roaring washer..

Cerwyn wrote:

OK, what you may be able to try then is making a new washer to the same thickness as your standard ones but open the bore out slightly. This might allow the cap to puncture which should in turn let more sound and smoke vent out.
If the gun still doesn't fire properly, try a slightly thicker washer.

Could you measure your cartridges please? If you can let us know the overall length and diameter we can check through the Cartridge Library for any matching cartridge.  


Just checking back to your original photos of the Suzuki cartridges, I notice the cartridge washer has a recess on one side. The Roaring Plugs are not recessed at all.
In that case, your Detonator Pin wouldn't "sink" into the Plug, making it push the Plug and cap harder against the cartridge's Firing Pin.
This may just strike the cap harder giving better ignition and punch a hole in the cap at the same time.

here is my washer..


if i turn it around in the gun and shoot it makes a nice bang.. but doesnt recoil..

If you turn it around, pin in barrel doesn't enter that washer, but pushes the whole washer.
This means you gain "depth-of-conical-hole" travel distance, and this is likely the reason the cap goes bang. Experiment seems to confirm that for some reason cap is not detonated hard enough.

Disadvantage of this method is that pin has much smaller area of contact with the washer, and its tip can get deformed when washer pushes it back during blowback.

Lack of recoil could be gas escaping from cartridge without pushing hard enough. It should normally expand pushing on cartridge bottom and on cap+washer+pin until washer hits end of cartridge. Pin leaves the hole and at that point smoke/sparks can exit cartridge through holes in cap/washer/cartridge tip, while blowback continues.
Shape of washer (conical hole) helps to seal both parts. I guess when washer is installed the other way around, gas could escape around it. Other models use just plain washers with cylindrical hole though. Minuscule differences can make huge change in how modelgun works :-/

Does your washer sit tight in the cartridge? Maybe it has too much free space on sides, and gas bypasses the washer?

i dont have any materials to make a washer right now.. kinda sucks.. i can slim down a washer right now i guess.. so marushin 7mm caps smoke and spark? i was gonna get the flaming caps but if marushin does both i can just get them.. im getting upset with this damn gun... close to selling it already lol.. i just want a working m9 lol.. i believe these caps are prob 10+ years old.. hopefully thats the only issue..