SpudFiles

VH_man wrote: MarkHFq: remember that GGDT does not take into account the fluid dynamics involved in the flying projectile. the golf ball has little divits that technically should give it a backspin, causing longer range. thats why golfers can hit the ball so far. its not because they hit it really hard, its because of the backspin.......... i can hit 250 yards without putting ANY power into the club (well some, but alot less than i can do)....

The golfball gets longer range because this action creates a lower drag, meaning a lower drag coefficient. A Cd of .5 is a perfect sphere or smooth cylinder, so I chose something a little lower to simulate a golfball.

I like that spudgun very nice !!!

That thing is a beast! Wow...

I am going to start making a list of people who make ridiculous range claims.[/quote]

That's the best idea i've heard all day, it seems some people like to live in fantasy land!!

Peace
Scotty

Man you got a quad and i've only got a skateboard

So this is really old but Mark.F. and I finally got a more accurate measurement of the muzzle velocity (originally estimated at 580 fps). Mark.F. built a basic chronograph and we did several shots at different pressures and got a consistent reading of 830 fps. In a vacuum, it will go about four miles, provided it travels in a straight arc at 45 degrees. Factor in air resistance and junk, I think it is safe to say it will achieve a half mile.

Here is the updated design. Same design but different aesthetically.[/img]

Using both GGDT's built-in range calculator and a quadratic air drag model with a generous drag coefficient (in excel using a 10ms time step) I get a range of about 1000 to 1300 feet (under 400 meters or 1/4 mile). Still pretty respectable.