what affects the efficiency of the spudgun?
816067
top of my head:\n- the material lining the barrel (friction)\n- the tightness of the fit of the spud inside the barrel (air leaks)\n- the length of the barrel (longer is generally more powerful)\n- the gas compression mechanism (higher presser is better)\n- the release/firing mechanism (faster is better)
946504
Intensity varies as the square of the distance.\nThat should help
205539
Depends on how large the strick is.  It would need to be very large to have any effect at all.
296912
Excessive is the wrong word, normal firing will discolor them over time. But if you mean that "rainbow" effect that some of them have, then yes, that is caused by excessive firing, the barrel overheated and lost some of its strength.
869876
.  Such a gun would be difficult or impossible to make.  Friction with the other air would cause your project stream flow to become turbulent very quickly.  Special nozzle design could improve the length over which the high pressure flow held together, but getting the flow to hold together for 20 nozzle diameters would be something which has never yet been accomplished.  That would mean that a 1 inch diameter nozzle would produce a flow which was no longer tightly focused 20 inches from the gun.  And, to produce such a high pressure with any useful amount of air, the gun would have to have a very heavy walled pressure tank.  \n.  Where air charge guns are used to some effect, the inoculation of large groups of people, like in the Army, pressurized air is supplied by a hose from an air compressor or a pressurized air tank.  This is not a very portable system.
1074897
absolutely, the military is working on one right now for there new electric battleship (in 2011). However, a railgun doesn't use heat to accelerate a projectile and the heat is just a sideeffect. a rail gun uses two electricaly charged superconductive rails, hence the name, to creat a super strong magnetic field around the armerture to fire the slug. The slug is made from DU(depleted uranium) or tungragen so it woudn't turn into a beam. Real railguns have the distructive energy as a small nuke without the radiation and complex dilivery system. a cheap 40 kilogram (about 75 pounds) can vaporize a target 600 miles away in a few minutes. the barral volocity is many times that of a regular gun and can be as high as Mach 9
158383
You have to shoot it from a far enough distance not to make it go farther than the half meter the bullet would cause it to go.It would also depend on where you hit the tin can. That would have an effect on it's travel.
59800
There are two issues at hand.  One is energy.  The other is momentum transfer.  \n\nHere are some muzzle energy for factory loads of the two rounds.\n\n30-30 factory loads:\n150 grain round - 2,390 fps - 1,902 ft. lbs energy\n170 grain round - 2,200 fps - 1,827 ft. lbs energy\n\n7mm factory loads:\n140 grain round - 3,400 fps - 3,593 ft. lbs energy\n160 grain round - 3,200 fps - 3,637 ft. lbs energy\n\nThe 7mm clearly has the uupper hand here.  However, that energy needs to be delivered to the deer to be effective.  Or more correctly, the momentum of the round needs to be transfered to the deer. \n\nThis is where, for example, hollow points are preferable to full metal jackets.  The hollow point will cause the bullet to mushroom giving it better momentum transfer properties (and therefore knockdown power).  FMJ rounds tend to go straight through causing somewhat less damage because of less momentum transfer.\n\nYou want a careful balance here.  Too much energy in too small an animal will make things, let us say, much messier.  All you want is a clean take.
815673
OK I'm cheating - I put this answer up a little while ago.\n\nA quick and dirty idea for a physics project would be one based on electromagnetism. Without knowing what grade you're targeting, a simple one that has a fair amount of pizzazz is to build a gauss rifle. Checkout http://sci-toys.com/scitoys/scitoys/magnets/gauss.html\n\nThe sci-toys site has some other pretty cool stuff that you might find useful as well.\n\nFor a more advanced example, you can make a small rail gun that applies similar principles but can have a much larger kick. Just do a search on "rail gun experiment".\n\nEnjoy!!
477619
If you are using round ball then the old method was to place a ball in your hand and use just enough powder to cover the ball. But it's not really a serious problem as you can't really overload a modern black powder weapon. The only problem you would have is seating the ball enough on a revolver for the cylinder to index. I've overloaded one enough that I had to trim the ball.\n To make it easier for you just buy a powder flask which will premeasure the load for you.\n Make sure you seal all of the cylinders after you have it loaded to prevent a cook off of all the cylinders at one time, it gets really interesting when that happens.\n If you've never used black powder before it's a lot of fun, a little messy but well worth it.
811403
I've included the links to manuals for both weapons. Good luck!
1141618
I have found for my gun which is a mossberg 500 slugster that rifled federals work the best.  I have had problems with winchesters. they jammed up my gun.  Don't use sabots unless you have a rifled barrel
786520
The muzzle velocity of the paint ball gun is higher. \nhttp://en.wikipedia.org/wiki/Muzzle_velocity
445418
No. It has potential energy. When you pull the trigger the potential energy is converted in to kinetic energy that does the intended work.
787170
Yes they do while your 1st burst will go okay there is good possibility of a jam on the next burst our 20mm phalanx gun did this several times much to the captains annoyance. The gun was brand new. Clearing a jam is a long messy maneuver as usually the feeder gears cut the shell casing of the jammed round. it's weird the gun will go several months without problem then it starts up again then goes away. Reloading these beasts isn't fun neither but until that new metal storm gun comes along this is the only weapon that fires this fast this accurately.
468847
the best kind is the tippmann 98 custom.  you can customize the crap out of it and still get more than your money's worth in accuracy.  plus it would be a mega gun that can compete with and costs less that an autococker.  Ive got a flatline barrel and stock on mine and i get really good performance out of it
1158833
i would have to say the ak/sks hands down. no matter if there is mud or water or anything. rack a round and that sob will shoot. unlike the m-16/ar-15 there prone to more jams. my romanian ak has never jammed on me that wasn't my fault. such as not loading the rounds right or having the tip not over the follower. my dpms panther has to be babied after 300 rounds.i have to clean the bolt and receiver out to clear out the build up of powder.