McFear wrote:is there a thread for HGDT cause its kinda confusing when not using it for a hybrid. i know it can be done, cause i have had people do it for me, but its kinda confusing to use for the first time.
You should read through the help pages on D_Halls site; http://www.thehalls-in-bfe.com/HGDT/index.html
To model a standard combustion gun set the mix (NX) to 1 and set the burst disk pressure to zero. A WAG for the friction value for a 2" spud is 10 PSI (30 pounds of static friction).
is there anyway of theoretically finding out how much distance i would get with a spud if i know the distance that a tennis ball went.
tennis ball (67g) went 180m at 5 degrees to the horizontal (video footage on youtube, search for scab1991 and watch) if i were to make a slug thats maybe 150 or 300 grams, is there anyway to hypothesise how far it would go.
It's kind of tricky to model the ballistics of a spud. Nobody knows what the coefficient of drag is and the spud tumbles so the drag and sectional density changes during flight. A tennis ball is much easier to model. I suspect that if you use D_hall's ballistic calculator you'll probably have to use a Cd of about 1.5~2.0. The calculator probably assumes the ammo is either a perfect cylinder or spherical. The distance estimate you get is probably not going to be very accurate. Joanna and ____? were working on a ballistic calculator for spudguns. Not sure what the current status is but I don't hink it has been released.
Someday, someone will finally measure the Cd of spuds from typical barrel sizes.