thompsonx
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Joined: 10/1/2006
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quote:
ORIGINAL: LetstalkboutRAP3
@DomKen
Momentum and energy are both always conserved. Where they go is the question. Momentum ultimately ends up in either the Earth or the air after moving through the weapon and/or the shooter.
Energy has all kinds of things it can do. It can turn into motion, light, heat, mechanical energy, deformation energy (bones, tendons, tissue)... When a given round is fired, and given rounds always contain (almost) exactly the same amount of chemical energy (powder charge), if it is fired from a semi-automatic some of it's energy is used to perform the work of ejecting the spent casing and loading the next cartridge. That is energy that is then unavailable to do anything else, like, say, hit the shooter in the shoulder.
No that is energy that is not used to propell the bullet down range. Remember the cartridge has been fired and all of the energy is expended against the bolt face. It is not until the bullet is almost to the end of the barrel that some small amount of the propelling gasses is scavanged to operate the mechanism... how much energy is used ? The barrel is .30" in dia. the scavange hole is about .010" since area is a exponential function it is easy to see that the scavanged energy is miniscule.
Semi-automatics have additional parts, which means more mass, which means the weapon accelerates backward more slowly. Slower acceleration over a given distance (stock to shoulder) means lower velocity. Kinetic energy increases linearly with mass, and exponentially with velocity. This is why semi-automatics produce less felt recoil than their manual feed counterparts, because there actually is less energy moving into the shooter. This is well established within the shooting community and supported by classical mechanics. It can be substantially less too, depending on the weapon and round in question.
Comparing like calibers and varying the weights of the weapon as you point out is a linier function. The two basic weapons being discussed are the 03 springfield and the m1 rifle. Only an approximate 10% difference in wt. Since all of the recoil energy is produced at the bolt face all of the recoil is felt. That initial felt recoil will be reduced as the extra wt absorbs it's percentage of the recoil. Thus the differences described by the term "percieved recoil"
The reason that snipers prefer manual feed weapons is because they are generally the simplest, most reliable, and most accurate weapons available.
Carlos prefered a ma duce...a fifty cal. machine gun that would fire single shot also.
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