With that valve and a long enough barrel and high enough pressure, I'm sure you can get pretty darn close. I'm guessing it would take 300 psi or so easily.D_Hall wrote:I've decided that I want to go for Mach with a golfball
Well, there is the whole problem of it being an unheated gas in there. Also, I'm not one to push valves much (if at all) beyond their ratings. This one is rated at 125. I won't go past 150 under any circumstances.jackssmirkingrevenge wrote:With that valve and a long enough barrel and high enough pressure, I'm sure you can get pretty darn close. I'm guessing it would take 300 psi or so easily.
D, Since I'm sure you've got a chrony laying around and access to a vacuum pump, how's about pulling a vacuum on the barrel and see what kind of measurable differance it makes, since we've just been theorizing about it up until now, look s like I'm a week or 2 away from a chrony of my own...D_Hall wrote:Golf ball gun, of course.
I'm torn... I've decided that I want to go for Mach with a golfball. I'm pretty sure I can do it, but it'd be a hybrid and would require some help from a friend (I can't weld for sh*t!). But that got me jonesing for a new golf ball launcher....
...So maybe I can't break Mach, but I can still go pretty quick with very little effort.
No.starman wrote:Are you planning to use that cute stainless sched 10 3 footer you just picked up for your barrel?
No idea. It's not an experiment that catches my eye, per se. I've worked with powder guns that had barrels under vacuum. It's a royal PITA. Unless I've got a very good reason, that's just something I won't be doing for "fun" because there's absolutely nothing fun about it.jeepkahn wrote:D, Since I'm sure you've got a chrony laying around and access to a vacuum pump, how's about pulling a vacuum on the barrel and see what kind of measurable differance it makes, since we've just been theorizing about it up until now, look s like I'm a week or 2 away from a chrony of my own...
I was just thinking that it may make mach more easily attainable, I've run the theory past some physics buffs I know and they seem to think that it will make a much larger differance in velocity and acceleration because the projectile will accelerate as if it was zero mass up to a point and by the object accelerating that quickly it will create a circumstance that will "trick" the pressured gases into behaving as they would in a vacuum, ie, increased mach #...D_Hall wrote:No idea. It's not an experiment that catches my eye, per se. I've worked with powder guns that had barrels under vacuum. It's a royal PITA. Unless I've got a very good reason, that's just something I won't be doing for "fun" because there's absolutely nothing fun about it.jeepkahn wrote:D, Since I'm sure you've got a chrony laying around and access to a vacuum pump, how's about pulling a vacuum on the barrel and see what kind of measurable differance it makes, since we've just been theorizing about it up until now, look s like I'm a week or 2 away from a chrony of my own...
I think you should find some "physics buffs" that actually know something about physics.jeepkahn wrote:I was just thinking that it may make mach more easily attainable, I've run the theory past some physics buffs I know and they seem to think that it will make a much larger differance in velocity and acceleration because the projectile will accelerate as if it was zero mass up to a point and by the object accelerating that quickly it will create a circumstance that will "trick" the pressured gases into behaving as they would in a vacuum, ie, increased mach #... (emphasis added)
What about the lack of air resistance in the barrel as the projectile accelerates?jimmy101 wrote:For a supersonic gun an evacuated barrel has a small advantage since you don't have to heat the air in the barrel hot enough to get it's speed of sound to be greater than the ambient speed of sound. But even that is a fairly minor affect.
