SACair Forum

:D

you can adjust your hop on me anyday.

good post steve i have always had the same thought oh well.

Wait, so the sign was walking?

:D

well, yeah bb's do travel at 360 fps compared to your standard 2800 fps in a rifle...so where is this confusion coming from?

*gives steve a hug*

no no what steveo is saying is that how come his rifle can hit a sign at a farther distance than a person whos closer. Gwad you noobs suck :lol:

[quote="spokey"]*gives steve a hug*[/quote]

ryan and his fabulous jew reading ability...

Indeed, just because you aimed your sights true does not mean you're going to hit your target. Even an APS2 shooting 550fps has some lag time from trigger click to impact.

:D

yeah, you are correct, as there are many factors i.e. wind resistance, wind, particles in the air, and the tempurature...im sure those contribute in some way or another.

is it just me, or did that seem rather obvious...

:D

as an engineer studying fluid mechanics the bb travelling through air behaves as a rotating sphere moving through a newtonian fluid (air) with loss in velocity due to frictional force as well as certain gravitational forces. at speeds around 360 fps (or about 110 meter/second) the dissipative force due to friction is fairly high. I would do the calculations for exact time for travel at 100' but im lazy...fair enough to say at 100' it will take a second or so to get out there and thats plenty of time for someone to move just enough for you to miss

I'm not claiming to have walked in as an expert, but I guess it's sort of as Krooked tried to impress everyone by saying, in way too complicated terms. However, I'd have to say that what probably helped me the most at understanding this concept from a very early stage was that I started my airsoft experience playing on my friend's property with just spring pistols. With that sort of thing, you really learn a lot about the motion of your bbs, proper arcing and leading techniques... just something to do with the fact that I didn't just jump into a sport I didn't fully understand, I worked my way in by understanding more and more about certain aspects... and in many aspects, I'm way behind many people on this forum, but there are things like this that I guess just come more naturally.

[quote="Krooked"]as an engineer studying fluid mechanics the bb travelling through air behaves as a rotating sphere moving through a newtonian fluid (air) with loss in velocity due to frictional force as well as certain gravitational forces. at speeds around 360 fps (or about 110 meter/second) the dissipative force due to friction is fairly high. I would do the calculations for exact time for travel at 100' but im lazy...fair enough to say at 100' it will take a second or so to get out there and thats plenty of time for someone to move just enough for you to miss[/quote]

[quote="Krooked"]as an engineer studying fluid mechanics the bb travelling through air behaves as a rotating sphere moving through a newtonian fluid (air) with loss in velocity due to frictional force as well as certain gravitational forces. at speeds around 360 fps (or about 110 meter/second) the dissipative force due to friction is fairly high. I would do the calculations for exact time for travel at 100' but im lazy...fair enough to say at 100' it will take a second or so to get out there and thats plenty of time for someone to move just enough for you to miss[/quote]

kyle's just trying to be cool. i would join in but i am only knowledgeable in biotranport/biological aspects of fluid mechanics, such as blood rheology and drug release and delivery; BB flight and trajectory is not my forte. air and blood have completely different reynold's properties and behave completely different outside of newtonian assumptions. kyle is correct in mentioning that a sphere is influenced by gravitational and frictional (fanning friction) forces, but it would be extremely complicated to calculate the velocity profile of the BB and the fluid around it due to outside discrepancies such as temperature, windage, etc.

oh, and one thing, with such knowledge of the behavior of flight through a fluid, kyle and i pwn noobs. lolerskates.

[quote="livesoundz"]kyle's just trying to be cool. i would join in but i am only knowledgeable in biotranport/biological aspects of fluid mechanics, such as blood rheology and drug release and delivery; BB flight and trajectory is not my forte. air and blood have completely different reynold's properties and behave completely different outside of newtonian assumptions. kyle is correct in mentioning that a sphere is influenced by gravitational and frictional (fanning friction) forces, but it would be extremely complicated to calculate the velocity profile of the BB and the fluid around it due to outside discrepancies such as temperature, windage, etc.[/quote]

[quote="ERIN"]Indeed, just because you aimed your sights true does not mean you're going to hit your target. [/quote]

so basically put the chrony 50' away from you to get a more accurate fps?

fps rules apply to muzzle velocity, the speed at which the BB exits the barrel. chronoing at 50' will just give you fps at that, the velocity after the BB has traveled 50'. this measurement will not be accurate. it's pretty obvious that the fps at 50' will differ depending on outside conditions, such as air density. by testing fps at the tip of the barrel, the BB is less likely to be affected by these variables because the BB is less exposed to wind resistance, etc. etc. also, the fps will be more consistent because the fps will be measured at an earlier time then if the fps were to be measured at 50' (ie, measuring fps at .001 seconds at barrel tip as opposed to 1 second at 50'). as soon as the BB leaves the barrel, it will no longer be accelerating and it will start to lose speed mostly due to friction.

i feel like an ass but i never thought that the bb would hit almost instantaneously. i mean its like paintball in the same sense that it takes awhile for it to hit you.