Is Specific impulse indicative of performance as a gun propellant?

In summary, the specific impulse of black powder is around 80s and rocket candy can reach up to 130s. This means that replacing a portion of the black powder in a cartridge with rocket candy would potentially result in similar performance in an idealized gun. However, specific impulse is not the only factor that determines a propellant's effectiveness as a gun propellant. The internal pressure of a cartridge is usually measured in cup, and firearms have upper limits on pressure that are influenced by the mass of black powder, projectile, and resulting impulse. Additionally, the property of brisance, which is related to the explosiveness of a substance, can also impact a propellant's suitability for use in guns. This is why TNT, which
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Christofer Br
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Is it that what increases propellants' specific impulse makes it proportionally a more powerful gun propellant?
Black powder has specific impulse of around 80s, while rocket candy has up to 130s of specific impulse. Does that mean I could replace the propellant in a BP cartridge with 80/130 of the weight in rocket candy and obtain the same performance in an idealized gun? (as in without considering burnrate, peak pressure and pressure vs time dependence)
Or is it that what increases propellants' specific impulse isn't making it proportionally a better gun propellant?
 
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Internal pressure of a cartridge using different propellants is usually measured in cup - copper unit of pressure
Get a reloading manual at the library and see what this means. Firearms have upper limits on pressure, which is related to the mass of bp, mass of projectile, and resulting impulse.

Propellants/explosives have a property called brisance: https://en.wikipedia.org/wiki/Brisance
Which is related to your question - it explains why TNT is not used as a propellant. There is an attached table in a link at the bottom: nitrocellulose (gun powder) is way down the list.
 
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1. What is specific impulse and how is it related to gun propellant performance?

Specific impulse is a measure of the efficiency of a rocket or gun propellant. It is defined as the amount of thrust produced by a given amount of propellant in a unit of time. In the case of gun propellants, a higher specific impulse indicates a more efficient propellant that can produce greater thrust and therefore, better performance.

2. How is specific impulse measured for gun propellants?

Specific impulse for gun propellants is typically measured in seconds and is calculated by dividing the thrust produced by the propellant by the weight of the propellant burned per unit of time. This measurement is often referred to as the specific impulse of the propellant.

3. Is specific impulse the only factor that affects gun propellant performance?

No, specific impulse is just one of many factors that can affect the performance of a gun propellant. Other factors such as the type and quality of the propellant, the design of the gun, and environmental conditions can also play a significant role in determining the overall performance of the propellant.

4. Can specific impulse be used to compare different types of gun propellants?

Yes, specific impulse can be used as a measure of comparison between different types of gun propellants. However, it is important to note that specific impulse alone may not be a comprehensive indicator of overall propellant performance and should be considered in conjunction with other factors.

5. Are there any limitations to using specific impulse as a measure of gun propellant performance?

Yes, there are some limitations to using specific impulse as a measure of gun propellant performance. It does not take into account factors such as the shape and size of the projectile, which can also affect the overall performance of the gun. Additionally, specific impulse may not accurately reflect the performance of a propellant in real-world conditions, as it is typically measured in controlled laboratory settings.

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