autocar

Different types of cartridges for Semi and full-automatics

Based on similar mechanism, model gun manufacturers have their ways to achieve the best model gun. As blow back force is very important for semi and full automatics, manufacturers focus heavily on cartridge design . Lightness, powerful, jam-free and easy maintenance are aims to design the best cartridge. Let's see how they achieve it.

A cut away view of model gun Beretta M84, note the barrel and firing pin system is different from real gun.

Most Popular cartridge system

Above three are the most popular cartridge system at present. Among the three, Tanaka built its cartridge from sketch. So it is the newest design I can say. Their performances are analyzed below.

Tanaka Parallel Division Cartridge
This new design is used exclusively by Tanaka's semi-autos. System is copied from CP-HW with some in-house improvements. Cap is placed on the prima and therefore only the valve will move when ignited. Only 5mm Cap cartridge is designed.
Number of parts: 6
Pros: very powerful, good sound and average spark, very light, easy to clean, , jam-free.
Cons: Difficult and complicated to load as it is 5mm, need cleaning very soon or jam occurs.

Marushin New Plugged Fire Cartridge
This new design is used exclusively by Marushin products. System is an improved version of Plugged Fire Cartridge. Cap is placed on the valve and therefore the valve and cap will move when ignited. Both 7mm and 5mm Cap cartridges are designed.
Number of parts: 6
Pros: quite powerful, good spark and sound, average lightness.
Cons: Difficult to load and clean as the prima O-ring can not be easily fitted. Mis-fired can happen if prima is not well placed, jam sometimes occurs.

MGC CP-HW Cartridge
This design is used by MGC itself, Kokusai, Tanaka's full-autos and Hudson. System is an improved version of CP cartridge. Cap is placed on the prima and therefore only the valve will move when ignited. Both 7mm and 5mm Cap cartridges are designed.
Number of parts: 5
Pros: very powerful, good spark and sound, average lightness, easy to load and clean, jam-free, .45 caliber is the best.
Cons: Best if lighter, .38 super caliber has feeding problems, O-ring detachment in 5mm cartridge.

MGC's development of cartridge
Before "Plastic Cap" was invented in 1981, "Paper Cap" is the only power source of model gun. Compared with Plastic Cap. Paper Cap is difficult to load and clean, and performance is pretty inconsistent. As soon as Plastic Cap (Cap) was invented, original CV cartridge was further re-designed to suit. MG cartridge is the result.

As you can see, no valves are present in MG cartridge. Cap is placed on the prima. The detonator is shaped so its front can be just as wide as the inner diameter of cartridge, forcing pressure to be built when ignited. This design failed due to some criticisms. When the detonator gets dirty after a few shots, it can easily cause jamming. The wide front design of detonator is also a concern as it makes feeding difficult sometimes. Cartridge can be easily deform in shape when it hits something hard. Solving all these problems is the development of CP cartridge.

A blank Cap is added to serve as a valve, so that the detonator can be narrower. Body is now two pieces to restricted the movement of valve when ignited. This is a excellent design as it is powerful, jam-free and good in sound as well as spark. Such system is further improved to CP-HW as more power is needed to pushed the Heavy Weight Slide. Therefore CP-HW cartridge is more air-tight with the use of O-ring.

Marushin's development of cartridge
Marushin had made a movement toward cartridge design after plastic cap was invented. Plugged Fire Cartridge is the result.

Different in philosophy, Cap is placed on the valve so that the cap will push the valve when ignited. Such system is simple as only 3 parts are used. But cartridge base is difficult to clean and power lose is massive. Therefore New Plugged Fire Cartridge is developed to provide better sealing with O-rings. Sadly, it is not as good as expected.

Little tips on autos cartridge

Clean cartridge immediately with water after fired, it is the best way to maintain cartridge.
MGC's CP-HW cartridge is so far the best cartridge in market. If you want something even better, Mulberry Field cartridge must be your choice. Marking are engraving on bottom of cartridge and it looks very cool. But you need to pay the price for quality. I can assure you if you get it, you will not fire them as it looks too good.
I think MGC .45 CP-HW cartridge is the best among all others, but don't fit it into your 92F.
Don't learn this if you are not well trained. For full metal autos, sometimes you need to put two Caps in one cartridge in order to make the heavy bolt work. Don't try this on your pistol, as you may end up with the slide stuck inside your face.
Revolver should use 7mm "B" Cap to achieve the best blowback action. The Cap itself is red in colour.

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