Tuesday, March 17, 2009

AirsoftBobby: 1000 Visitors For 3 Months

Ho0o0orayy.. Today, my visitor were recorded to be 1000 visitors for almost 3 month since this blog had been build.. So I would like to thank for those for support this blog since back then.. I will sure that this blog will long lasting until Airsoft were permitted to play in Malaysia.. Thanks again guys.. Cheers =)

p/s: I've ban my own IP in blogpatrol so that whenever i visited my blog, the blogpatrol won't record my IP as a visitor.. And once again, sorry for my bad english.. =p

Sunday, March 15, 2009

Info: How Ballistic Works

So now lets back to the business.. Forget the crap about last post. That's just about a commercial break done for someone else.. Lolx.. In this chapter, we gonna learn about how bullets work either for gun, machine gun, or other types of firearms.. First of all , we need to know what is explosion as the main cause of ballistic movement were related to fire and explosion.

Well I'm sorry to say that i can get any citation at the following notes because it comes from my lecture. A credited to Dr. Rafiziana Md. Kasmani by providing some of the following lecture:

What is Explosion:
A sudden chemical explosion of a flammable material (in this case, we use gunpowder) with oxygen action which causes a sudden a sudden formation of a great volume of expanded gas and release of high energy.

Early Concept of Ballistic:
You apply explosive pressure behind a projectile to launch it down a barrel. The earliest, and simplest, application of this idea is the cannon.

Figure 1: Flinlock-Cannon

Example: The Flintlock Cannon:
When you ignite [A] gunpowder [C], it burns rapidly, producing a lot of hot gas in the process. The hot gas applies much greater pressure on the powder side of the­ cannonball [B] than the air in the atmosphere applies on the other side. This propels the cannonball out of the gun at high speed. Now let's take a look the inside of the bullet catridge:

Ballistic Background: The Cartridge
Simply put, cartridges are a combination of a projectile (the bullet), a propellant (gunpowder, for example) and a primer (the explosive cap), all contained in one metal package. The primer will ignite the propellant

Example: Revolver
We going to see how the explosion occur in a firearm. In example, we'll see how revolver works.

Click on the trigger to see how the revolver fires.

This gun has a revolving cylinder, with six breeches for six cartridges. When you pull the trigger on a revolver, several things happen:

  1. Initially, the trigger lever pushes the hammer backward.
    • As it moves backward, the hammer compresses a metal spring in the gun stock (the handle).
    • At the same time, the trigger rotates the cylinder so the next breech chamber is positioned in front of the gun barrel.
  2. When you pull the trigger all the way back, the lever releases the hammer.
  3. The compressed spring drives the hammer forward.
  4. The hammer slams into the primer at the back of the cartridge, igniting the primer.
  5. The primer sets off the propellent. (Explosion Occur Here)
  6. The exploding propellent drives the bullet out of the gun at high speed.
The inside of the barrel has a spiral groove cut into it, which serves to spin the bullet as it exits the gun. This gives the bullet better stability as it flies through the air, increasing accuracy.

When the propellant explodes, the cartridge case expands. The case temporarily seals the breech, so all the expanding gas pushes forward rather than backward.


A sudden formation of combustion from propellent caused the bullet to explode and exits the gun by the ignition at primer of the catridge. Well that is only a few info on how the ballistic works in which relate to my study of combustion and explosion. More to come after this is on how the grenade works.


  1. Tom Harris, Contributing Writer (http://science.howstuffworks.com/)
    Tom Harris holds a B.A. in English from the University of North Carolina at Chapel Hill
  2. Dr. Rafiziana Md. Kasmani (B.Eng (Chem.Eng)(UTM), M.Sc. (Fire & Explosion Eng.), (Leeds)PhD.)

Sunday, March 1, 2009

New Invention: Heat Sink For Firearms Barrel

Background Of The Invention

Firearm have long had a problem of the barrel becoming overheated when a high number of rounds are fired in rapid succession through the weapon.

The barrel absorbs heat primarily from the combustion attendant to the firing of a weapon, and the heat produced both by the friction of the bullet and of the muzzle gasses leaving the barrel.

Disadvantages of Overheating Barrel
May lead to heat-induces changes within the metallurgical structure of the barrel. It may wrap the barrel, and, thereby, both increase the misfiring rate of the weapon and decrease its accuracy.

Overheated weapon is difficult to handle, position, and transport. Accordingly, it is desirable to force an increase in the rate of heat transfer of heat from firearms subject to such conditions.

The First Invention To Reduce Overheated Barrel
Several of device are intended to be permanently affixed to the firearm, or to be integral to design of the firearm itself. Some have used water or air to cool the barrel; other have use muzzle gasses or a material closely attached to the firearm barrel to conduct heat away from the barrel in an efficient manner.

Automatic Gun (George Hookham, 1899): A ribbed, tapered barrel which is fluted toward the breach. The extreme rear end is smooth in order to fit into a bushing, which is contained in the body of the gun. A casing surround the barrel, so that a channel is formed between the casing and barrel.
George Hookham (1899) Automatic Gun

Air-cooled Gun (Scott Paine, 1942): A cooling jacket surrounds the barrel and and ribbed sleeve. The cooling jacket is pressed into the breach at the rear end. Figure as follows:

Scott Paine (1942) Air-Cooled Fun

All of these devices appear to require customization to fit each specific firearm. They do not appear to be easily removed or refitted to a different firearm. Many also have been dependent on forcing air or water through a cooling channel, sometimes disadvantageously necessitating the use of auxiliary equipment.

It is, therefore, readily apparent that there is a need for an improved firearm heat sink that is easily attached to the barrel of firearm; that provides for easy removal and refitting to another firearm; and, that is lightweight, easy to manufacture, can be rapidly installed, and will easily adapt to a wide variety of firearm.

Final Solution: Invention of Heat Sink For Firearm Barrel (Todd A. Muirhead, 2003)

Brief Summary Of The Invention
The present invention both overcomes the above-mentioned disadvantages, and meets the recognized needs for such device, by providing a firearm heat sink which is easily removed from one firearm, and easily refitted to another.

In all embodiments, an underlying heat conduction material may be provided to fill gaps between the barrel and heat sink, and to provide adequate contact there between.

Thus, it is an object of the present invention to provide new and improved heat sink for mounting upon the firearm which can be easily fitted and refitted to a variety of firearms, fit a variety of sizes of firearm barrels, can be rapidly installed and easily manufactured. More detailed will be discuss by following figures:

Figure 3 (Fig.1 in Picture): Perspective view of the firearm heat sink of the present invention having one ring remove and one ring in place.

Figure 3a: Sectional view of the firearm heat sink showing a non-round cross section.

Figure 4: Perspective view of the preferred embodiment of the firearm heat sink attached to a firearm.

Figure 5: Perspective view of the two facing tubular halves of the firearm heat sink of the first alternate embodiment.

Figure 5a: Sectional view of the heat sink of the first alternate embodiment showing a non-round cross-section.

Figure 6: An exploded perspective view of the first alternate embodiment, in position to be mounted upon a firearm barrel.

The following picture shows a better understanding of heat sink mostly for all user. The engine block of a motorcycle or even a car uses almost the same concept of heat sink that invented to reduce heat in engine. The same concept goes to the invention of heat sink for firearm barrel.

Engine Block used a heat sink to increase the rate of heat transfer between the engine and the environment.

The other good example of heat sink for firearm is the HK 416 as taken from youtube.com as follows: