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Whats far for a golf ball?

Posted: Sun Apr 26, 2009 12:56 am
by Moonbogg
HGDT says a new design will send a golf ball about 400 yards. That doesn't sound too terrific to me. Then I searched to find out how far they have been hit by golfers, and its between 4-500 yards.
I punched in a heavier round into HGDT and although the velocity was less, the distance was farther. I am guessing 4-500 yards is sort of a terminal range for a golf ball kind of like a potato only going around 200 or so. How far is far for a golf ball out of a cannon?

Posted: Sun Apr 26, 2009 1:02 am
by MountainousDew
Is that prediction at an angle or is it a straight shot?

Either way, I would be happy as long as the velocity is uber fast...

Posted: Sun Apr 26, 2009 1:44 am
by Moonbogg
thats at an angle of about 30°

Posted: Sun Apr 26, 2009 9:34 am
by mark.f
Did you get a read on the velocity at impact?

Re: Whats far for a golf ball?

Posted: Sun Apr 26, 2009 10:09 am
by Technician1002
Moonbogg wrote:HGDT says a new design will send a golf ball about 400 yards. That doesn't sound too terrific to me. Then I searched to find out how far they have been hit by golfers, and its between 4-500 yards.
I punched in a heavier round into HGDT and although the velocity was less, the distance was farther. I am guessing 4-500 yards is sort of a terminal range for a golf ball kind of like a potato only going around 200 or so. How far is far for a golf ball out of a cannon?
On our test field with the t shirt air cannon, we lost balls beyond the 400 yard range we were using. Don't know the distance. Didn't find any in the brush beyond the tennis courts. :)

Take a few shots and see if you can find them. At that range, the direction of the wind makes big changes. I consider range testing golf balls lost balls. My eyes are not good enough to even identify the landing zone, They make a tiny hole in the sky and are sucked into it never to be seen again. :D They go up, shrink and vanish. I rarely see them come down.

Posted: Sun Apr 26, 2009 10:26 am
by starman
I've gotten in the 650 yard + rangewith Trip Thunder and 78" barrel, slight breeze behind me from the North Northwest.

Posted: Sun Apr 26, 2009 10:45 am
by SpudsMcGee
starman wrote:I've gotten in the 650 yard + rangewith Trip Thunder and 78" barrel, slight breeze behind me from the North Northwest.
I might be wrong, but didn't you use MAPP Gas...
That may be the reason your gun, Starman would shoot farther than MoonBogg's.

Posted: Sun Apr 26, 2009 10:55 am
by starman
SpudsMcGee wrote:
starman wrote:I've gotten in the 650 yard + rangewith Trip Thunder and 78" barrel, slight breeze behind me from the North Northwest.
I might be wrong, but didn't you use MAPP Gas...
That may be the reason your gun, Starman would shoot farther than MoonBogg's.
Yep using MAPP. I don't think Moonbogg has a measured shoot yet...if I'm reading his post correctly...just an HGDT estimate. 400 yards is fairly easily attained for a golfball shooter.

Posted: Sun Apr 26, 2009 1:31 pm
by jimmy101
starman wrote:400 yards is fairly easily attained for a golfball shooter.
That's probably true. 400yds is also probably about the maximum range possible without either a very large gun (chamber and barrel) or some other way of boosting the chamber energy by a significant amount.

All ammos have a maximum practical range. Seems to me that it is basically the relationship between the sectional density and drag. For spuds perhaps 200 yards. For tennis balls roughly the same? Golfballs are denser so perhaps 400 yards.

Tha challenge in getting greater range is that as you boost the muzzle velocity you boost drag. So you get into a "diminishing returns" domain. You have to boost the muzzle velocity by a lot to get even a modest increase in range. To get a golfball to go 600 yards instead of 400 yards is going to take a pretty big boost in energy. (Assuming you've already optimized launch angle etc.) If you start to approach the SOS then the required incremental energy goes way up.

You can fiddle with GGDT's range calculator to get an idea of how much you need to boost the gun's energy to get a particular increase in range. Using the default gun and ammo in GGDT you have to make both the chamber and barrel 400% longer to increase the range by just ~30%.

Posted: Sun Apr 26, 2009 1:34 pm
by Moonbogg
starman wrote: Yep using MAPP. I don't think Moonbogg has a measured shoot yet...if I'm reading his post correctly...just an HGDT estimate. 400 yards is fairly easily attained for a golfball shooter.
Yes thats right, just an HGDT estimate right now. Its actually a 3x hybrid that supposedly only lobbed the ball 400 yards. I actually made the design a little smaller to lose some weight, and now it only tossed the ball 280 yards!!! I could probably hit the ball with a bat farther than that if I got really lucky (maybe not, but still).
The later estimate was using a 2" SCH40 x 10" chamber with 1 1/2" SCH10 x 48" barrel @ 3X

Oh Starman, nice range on that sick shot.

Posted: Sun Apr 26, 2009 3:16 pm
by psycix
If you start to approach the SOS then the required incremental energy goes way up.
So I now wonder, what happens if your projectile happens to travel above the SOS? Here we would be talking about a high-sectional density, aerodynamic projectile. Probably sabot.
Since the Cd drops significantly after going above the SOS (but not less then it ramped up before the SOS), the actual drag will remain about the same for a set range of velocities. Now get your projectile's muzzle velocity right at the top of that sweet spot and you will need to find a very large shooting range.

Posted: Sun Apr 26, 2009 3:48 pm
by Moonbogg
Excellent points made here. I will be satisfied with 4-500 yards from HGDT since that appears to represent a good practical range, so long as muzzle velocity stays high enough to cause some fun damage (maybe 700+) ? That sounds like a good damage speed to me. HGDT puts the Venom at 2X with a 30psi burst disc at around 830fps. The compromise in raw power due to the size of the gun will be worth it for the uninterrupted shooting a multi chamber, yet more compact gun will provide.

Posted: Sun Apr 26, 2009 3:55 pm
by POLAND_SPUD
@ psycix even if something is fired at speed above the SOS it will slow down and experience high cd values...

for an average spudder it's a better idea to use heavier projectiles which will experience lower cd values and have high sectional density

Posted: Sun Apr 26, 2009 4:01 pm
by jrrdw
10 MILES! :roll:

Posted: Sun Apr 26, 2009 4:04 pm
by jagerbond
POLAND_SPUD wrote:@ psycix even if something is fired at speed above the SOS it will slow down and experience high cd values...

for an average spudder it's a better idea to use heavier projectiles which will experience lower cd values and have high sectional density
if only they made tungsten carbide golf balls.

Mike
Sureshot Inc. / http://www.ultimatespudgun.com