Más cosas sobre el tema este de los cilindros y los ratios.
En este caso sobre snipers. Al parecer, para usar bolas pesadas y no perder energía, los ratios deberían estar por encima del 2.5. En base a esto, he leído en varios sitios que el tamaño "optimo" de un cañón muchas veces se calcula en base al volumen del cilindro.
Y ahora, algo más de info sobre esto de las potencias equivalentes:
Now in both cases, BB weight can cause various muzzle velocities without changing the spring. This is because a higher-powered gun is forcing air out that much faster. Thus, a light BB might be expelled very quickly by that initial burst and not reach the energy that the gun is actually capable of......in other words, if a heavier BB is used in that same gun, you can actually see a muzzle energy increase because the BB is heavy enough to not be shot forward by that initial burst. This means the full volume of air is behind it moving quickly, and it reaches full acceleration as it exits the barrel. A BB that reaches full acceleration earlier in the barrel will actually slow down as there is no force behind it anymore, so it is traveling on inertia alone and frictional forces, due to air and also the walls of the barrel, act to slow it down. This is relevant because with high-powered sniper rifles, testing is done with a .2g BB. This is faulty because the gun is tuned to shoot with a heavier BB, like .34g or greater, let's say. Thus, that lighter BB may exit the barrel before the full energy potential is reached. For instance, there have been cases where somebody will chrono at 490fps with a .2g BB which equates to 2.2J of energy. Then, they chrono with a .36g BB at 420fps which equates to 2.9J. Same gun, very different muzzle energy because of what I outlined above. That is where muzzle energy comes into play and is a better indicator of a gun's energy capability than pure velocity. You can see how that could come into play at the chrono pit, and a player innocently and unknowingly is wielding a gun that is shooting at higher muzzle energy than expected.
This is usually only seen in higher-powered guns, but can be seen in our regular AEGs as well to a smaller degree. For example, let's say you have a gun chrono at 400fps with .2g BB, which equates to 1.48J. I have seen multiple common instances where that same gun will then chrono at 360-370fps with .25g BB, which equates to 1.49-1.58J. See how the energy rise was slight, although the gun legally shot 400fps with .2g BB?
Thus, the relationship is not linear, but is dependant on parts in your gun, including the nozzle, tightbore barrel, piston head, cylinder, cylinder head and inner barrel length. Furthermore, if those parts aren’t sealing well, that throws a bit more variance into the mix. However, due to experiences with various guns, you can get a feel for where a gun should lie in the muzzle velocity range based on what BB is being used. So your statement about expecting a gun to shoot anywhere from 25-50fps higher with a .2g BB versus a .25g BB, as a loose general number, is accurate, although in my general experience I would typically say 30-40fps is a more likely number. I threw out 25-50fps earlier to incorporate more variables.
The same discussion mentioned above for sniper rifles and regular AEGs also applies to support weapons. For example, one of my RPKs chrono'd at 442-447fps consistently at the last Roanoke op with .2g BB, and prior to going to that op, I had checked it at home with .25g BB to be anywhere from 401-411fps. The .2g BB energy works out to 1.79-1.87J, whereas the .25g BB works out to 1.85-1.94J, so you see how the same gun can produce slight muzzle energy differences just because of the BB.
Traducción rápida y corta. Las notas entre paréntesis son anotaciones mías dando por cierto las suposiciones anteriores:
El peso de la bola puede generar diferentes energías en la boca del cañón sin cambiar el muelle. Una bola ligera tiene mucha más velocidad y abandona el cañón antes de haber podido aprovechar toda la presión del aire, sobre todo si hay una presión de aire inicial violenta.
Una bola más lenta absorbe más energía de la presión del aire por que se mueve más despacio, y eso la permite aprovechar más la presión generada por el conjunto neumático antes de abandonar el cañón. (Y si ha esto le unes una presión más constante por un ratio C/B más alto... más se incrementará la energía que absorbe).
Esto es importante por que en las réplicas de sniper, el testeo se realiza con 0.20. Esto es un error por que la bola abandona el cañón antes de que se haya desarrollado toda la energía potencial. Hay casos de réplicas que al pasar crono con 0.2 dan una velocidad de 490FPS (eq. 2.2J) y después al poner bolas de 0.36, la velocidad es de 420FPS, lo que equivale a 2,9J.
Misma réplica, misma config, diferente energía en la salida del cañón. La energía es un indicador mucho más fiable que la velocidad de la verdadera potencia de la réplica.
Esto se ve sólo normalmente en réplicas de alta potencia, pero se da en menor medida en AEGs (en parte puede estar ocasionado por que la mayoría de réplicas tienen ratios de C/B menores a 2). He visto (el autor del post) varios casos de réplicas que dan 400FPS con 0.20 (eq. 1,48J) y después su velocidad con 0.25 es de 360-370FPS, lo que equivale a 1,49-1,58J.
Pues eso. Este viernes hago pruebas y a ver si salgo de dudas con todo este embrollo.
