Why only paintballs

I just heard, in our school's Lifetime Fitness gym class,(you go paintballing in it), a person brought a marble to school, put it in one of the guns and shot it at a roll of carpeting.

If only i was there and knew about it.  I guess the stupid kid shot another kid in the back of the head when no one had masks on.

Langside wrote: Hamster in barrel... Messy.

One of my friends wanted to try his hamster in his spud gun once...

thankfully the hamster was sleeping in his cage and out of reach of my friend...

General_Lee wrote: As I'm not stupid enough to shoot foreign objects from my A5 I have tried and with good results... sometimes... inserting another PAINTBALL down the barrel  so it contacts the first, then shooting both .....  it works accuratley sometimes... not always its easier and works better to just go full auto.

Not to mention you don't have to risk breaking a ball shoving it down your barrel..

i do know someone who has shot marbles out of their gun, it scratched up the inside of the barrel, and did some wicked damage to the wood he was aiming at...

Its stupid to put stuff in your gun that doesn't belong... anyone dumb enough to do it should not be allowed to own a PAINTBALL gun

THE WARS WILL CONTINUE!

usafpilot07 wrote: Mack wrote: usafpilot07 wrote: Removing the velocity screw on a Tippmann(ProCarbines at least) increases velocity.  Riot squads using pepperballs and other deterrents use this method to increase effectiveness.  The gun used was some type of tippmann, as the case was all over PBN when it happened. The velocity screw on stock Tippmann 98s, A5s and X7s works by interrupting the airflow between the valve and the chamber. In essence, when the screw is screwed farther in, it blocks the air passage and slows the rate/volume of air release. The same amount of air is released, but the rate is effected. It's been awhile since I got rid of my Pro-Carbine and 68 Carbine, but I seem to remember them working in the same way. With this in mind, you can crank the velocity up on a Tippmann by turning the screw out. However, once the screw no longer protrudes into the air flow, no further gain in velocity is achieved. In fact, it is contended that a slight velocity loss could occur from going past this point (approximately 4 turns out from all the way in) because a negative void is created in the air chamber which allows further expansion of the released propellant, thus reducing chamber pressure. At a certain point, if the screw is backed out far enough, air leakage around the velocity screw could also have a negative effect on velocity. Now, if you remove the screw entirely, you just left an opening of approximately 7mm in diameter for your propellant gasses to leak out of without propelling the projectile. When you consider that the approximate barrel diameter is 20mm, you have avout 25% of your propelling gasses being wasted by direct venting into the atmosphere. All in all, I don't see how removing the velocity screw from a Tippmann would increase the velocity. As a side note on the Pepperball markers, I remember reading when they first came out that the internals/springs had been strengthened for Law Enforcement use. They had a warning at the time that the markers could not be safely used for regular paintball play. The negative effect of the void would be negligible after the first few shots. This is just a rough sketch, but it should show what I mean. In the top image, it would represent having a velocity screw screwed in.  This forces air molecules through a reduced space.  But, in the lower image, it shows that the amount of airflow gained by  removing the velocity screw is greater than the amount of air molecules that can escape through the gap.

It's a nice picture, but basic math and fluid dynamics prove it incorrect.

One thing I should have mentioned earlier that probably makes the velocity argument moot anyway is that it is doubtful that a good screw to barrel match was achieved. It wasn't the velocity that made the screw dangerous, it was its shape and density.

Edited Note: Your pics prove my point. Note in your illustration that if you back the velocity screw out to where it is flush with the inside of the tube, you have unobstructed and complete air flow. In the second pic, where it is removed, you still have unobstructed airflow but not complete airflow.


Edited by Mack - 15 February 2007 at 9:29pm

usafpilot07 wrote: Removing the velocity screw on a Tippmann(ProCarbines at least) increases velocity.  Riot squads using pepperballs and other deterrents use this method to increase effectiveness.  The gun used was some type of tippmann, as the case was all over PBN when it happened.

The velocity screw on stock Tippmann 98s, A5s and X7s works by interrupting the airflow between the valve and the chamber. In essence, when the screw is screwed farther in, it blocks the air passage and slows the rate/volume of air release. The same amount of air is released, but the rate is effected. It's been awhile since I got rid of my Pro-Carbine and 68 Carbine, but I seem to remember them working in the same way.

With this in mind, you can crank the velocity up on a Tippmann by turning the screw out. However, once the screw no longer protrudes into the air flow, no further gain in velocity is achieved. In fact, it is contended that a slight velocity loss could occur from going past this point (approximately 4 turns out from all the way in) because a negative void is created in the air chamber which allows further expansion of the released propellant, thus reducing chamber pressure. At a certain point, if the screw is backed out far enough, air leakage around the velocity screw could also have a negative effect on velocity.

Now, if you remove the screw entirely, you just left an opening of approximately 7mm in diameter for your propellant gasses to leak out of without propelling the projectile. When you consider that the approximate barrel diameter is 20mm, you have avout 25% of your propelling gasses being wasted by direct venting into the atmosphere.

All in all, I don't see how removing the velocity screw from a Tippmann would increase the velocity.

As a side note on the Pepperball markers, I remember reading when they first came out that the internals/springs had been strengthened for Law Enforcement use. They had a warning at the time that the markers could not be safely used for regular paintball play.

the velocity screw doesnt matter.  the idiot was still dumb enough to put a foreign object into the gun and shoot it at a little kid.  ppl r just too dumb nowadays

usafpilot07 wrote: Are you really that dumb?  You do know that screws are extremely sharp at the point right? Not only that, but the marker that was fired from had it velocity screw removed.  I fail to see how you linking to an instance of a young child dying due to a sharp object(just like I said) from a hot gun; to a kid who took his mask off during the game. I mean, unless you just happen to drop the occasional screw into your hopper.

I didn't see in the article where it specified the gun was hot or the velocity screw was removed. Neither was the type of marker specified. However, if the marker was a Spyder clone, removing the velocity screw would decrease velocity as it decreased the pressure on the spring and would not result in a hot gun. If the marker was a Tippmann or BE, removing the velocity screw would also decrease velocity as air pressure would be lost through the screw hole.

Of course, neither of these may apply if there is further info I have not found yet.

Edited Note: Additionally, the gun would probably not need to be hot for a pointed object to be dangerous. The much smaller intial contact area of the projectile concentrates the kinetic energy onto a single point as opposed to dispersing it like a paintball shaped projectile does.


Edited by Mack - 15 February 2007 at 1:40pm

Langside wrote: usafpilot07 wrote: $400 98custom wrote: any projectile u shoot out of a weapon is lethal. in this case, a paintball, when shot normally doesnt have anough power to kill unless u hit on the money.  any other object can kill.  bottom line: shooting anything other then normal UNFROZEN paintballs is dangerous and should not be done by anyone Have you not read any of this thread?  A paintball can NOT kill you.  Unelss of course, by "on the money," you mean that a surgeon happens to bring out a paintball gun in the middle of open heart surgery, then it's not possible.  I've already tried to explain to everyone that 300 feet per second is not enough force and kinetic energy to kill you with anything short of a razor sharp object.  Guess what happens when you put a marble in a paintball gun?  It's velocity is lower than 300fps because it has MORE MASS x the constant FORCE.  Therefore, no, you won't die unless you have a pre-existing medical condition or an open surgery tray over a major organ/artery/vein. AND FROZEN PAINTBALLS ARE MORE BRITTLE THAN A NORMAL PAINTBALL.  FOR GOD'S SAKES, PROFESSIOINAL TEAMS OFTEN KEEPS THEIR CASES ON ICE AND IN COOLERS FOR THIS VERY REASON. DON'T YOU THINK WE WOULD HAVE HAD A DEATH BY NOW IF THAT WEREN'T THE CASE? Langside wrote: $400 98custom wrote: when shot normally doesnt have anough power to kill unless u hit on the money.  My point exactly, he could have died. No. He. Could. Not. Have. http://www.kvia.com/Global/story.asp?S=5084326 YES. HE. COULD. HAVE. TWAT

Are you really that dumb?  You do know that screws are extremely sharp at the point right? Not only that, but the marker that was fired from had it velocity screw removed. 

I fail to see how you linking to an instance of a young child dying due to a sharp object(just like I said) from a hot gun; to a kid who took his mask off during the game. I mean, unless you just happen to drop the occasional screw into your hopper.

id love to see that