 WARNING: Description
Specifications
IMR 8208 XBR Smokeless Gun Powder
Delivery Information
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Shipping Weight  |
8.400 Pounds |
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DOT-Regulated  |
Yes |
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Carrier Restrictions  |
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IMR 8208 XBR Smokeless Gun Powder is a Smokeless powder which is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to gunpowder (“black powder”). The combustion products are mainly gaseous, compared to around 55% solid products (mostly potassium carbonate, potassium sulfate, and potassium sulfide) for black powder.[1] In addition, smokeless powder does not leave the thick, heavy fouling of hygroscopic material associated with black powder that causes rusting of the barrel. Despite its name, smokeless powder is not completely free of smoke  while there may be little noticeable smoke from small-arms ammunition, smoke from artillery fire can be substantial.
IMR 8208 XBR Smokeless Gun Powder
The properties of the propellant are greatly influenced by the size and shape of its pieces. The specific surface area of the propellant influences the speed of burning, and the size and shape of the particles determine the specific surface area.
By manipulation of the shape it is possible to influence the burning rate and hence the rate at which pressure builds during combustion. Smokeless powder burns only on the surfaces of the pieces. Larger pieces burn more slowly, and the burn rate is further controlled by flame-deterrent coatings that retard burning slightly. The intent is to regulate the burn rate so that a more or less constant pressure is exerted on the propelled projectile as long as it is in the barrel so as to obtain the highest velocity.
The perforations stabilize the burn rate because as the outside burns inward (thus shrinking the burning surface area) the inside is burning outward (thus increasing the burning surface area, but faster, so as to fill up the increasing volume of barrel presented by the departing projectile). Fast-burning pistol powders are made by extruding shapes with more area such as flakes or by flattening the spherical granules. Drying is usually performed under a vacuum. The solvents are condensed and recycled. The granules are also coated with graphite to prevent static electricity sparks from causing undesired ignitions.
IMR 8208 XBR Smokeless Gun Powder
Currently, propellants using nitrocellulose (detonation velocity 7,300 m/s (23,950 ft/s), RE factor 1.10) (typically an ether-alcohol colloid of nitrocellulose) as the sole explosive propellant ingredient are described as single-base powder.
IMR 8208 XBR Smokeless Gun Powder
Propellants mixtures containing nitrocellulose and nitroglycerin (detonation velocity 7,700 m/s (25,260 ft/s), RE factor 1.54) as explosive propellant ingredients are known as double-base powder. Alternatively diethylene glycol dinitrate (detonation velocity 6,610 m/s (21,690 ft/s), RE factor 1.17) can be used as a nitroglycerin replacement when reduced flame temperatures without sacrificing chamber pressure are of importance.  Reduction of flame temperature significantly reduces barrel erosion and hence wear.
IMR 8208 XBR Smokeless Gun Powder
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