Rubber gun technology is based on the availability of suitable elastic bands.  We traditionally used strips and bands cut from the inner tubes of automotive tires.  Since the advent of tubeless tires, this material is increasingly hard to find.  But "inner tubing" on snow is still popular, and the tubes must come from somewhere.  Industrial and truck tires still use tubes discarded ones might be found at service stations that engage in this kind of work.  Ruined tubes, no longer fit for service, do just fine for our application and might be free for the asking.  Live rubber is extinct, having been replaced by butyl (synthetic) rubber in the 40's.  Butyl is good and is much more durable than the product from rubber trees.  Motorcycle shops are a good place to look for old tubes.  Dirt bikes are particularly hell on tires and tubes.  Rubber bands, cut from motorcycle inner tubes, can be made longer by loop-knotting two or more together.  The ultimate material is surgical tubing but this must be purchased and is expensive.  We are interested in things that can be made without cost by a kid.  Don't be suckered by vinyl tubes, air mattresses, and wading pools because most plastics lack elasticity.
The basic pistol is made from a scrap of 1" board (usually 7/8" thick).  Referring to the high-class mechanical drawing, it can be sawed or whittled as one piece.  But the barrel and grip should be separate pieces (A) so that the grain runs in a direction to reduce breakage, as shown.  The grip is slender so that, with the clothes pin mounted, it can be grasped by an immature hand.  Only the front of the grip is tapered to give a little rake.  Two nails (B) fix the parts together and keep them from twisting crooked.  A small-diameter wood screw, replacing one of the nails, will keep them from prying apart.  Daddy saw me split a handle, driving a screw, and taught me about "pilot" holes (tap hole) for both nails and screws.  A pilot hole also makes a screw much easier to drive.  He gave me access to a small hand drill and his drill bit selection.
The top piece of the clothes pin (C) is removed so that a wire brad can be driven (D) to position the clamp (clothes pin) with the nose slightly below the top edge of the barrel.  A shallow notch (E) is carved into the muzzle of the barrel to retain a loaded rubber band.  To load the gun, a rubber band is clamped first and then stretched over the end of the barrel.  It is discharged by squeezing the grip assembly.  With only the coil spring to grip a band, very little stretching tension can be used.  A universally used method, of holding the projectile band tighter, is to twist a band tightly around the top of the clamp and the upper part of the grip.  Thus, the projectile can be stretched tighter, giving more velocity, range, and stinging power.  A simple knot in the middle of a projectile effectively shortens it to make it stretch tighter.  The knot also increases the range by cutting air resistance.  Projectiles can be effectively shortened by folding over a portion that goes in the clamp.
I invented this method of doubling the firepower of a rubber gun (two shots instead of just one).  (A) is the bottom half of a clothes pin and (B) is a #10 bolt. (C) are shallow depressions, in both the handle and clothes pin, to position the bolt.  A band is stretched tightly around the top of this first clamp and the upper part of the handle this has to be tighter than the final band applied to the complete assembly.  After the top half of the clothes pin is assembled, the first clamp is loaded first, followed by a normal loading of the second.  A normal squeeze lets the first shot go, and a more firm squeeze releases the second one.
My adversary thought I had shot all my rubbers and arrogantly swaggered toward me to finish me off.  I blew him away with my secret weapon and still had one loaded on my other gun.  Everyone soon learned not to depend on counting shots.  They would cautiously see if there was a rubber stretched over the muzzle of my gun.  The other boys eventually started using this device.  I always stretched a dummy band, end to end on the barrel, so that the gun appeared to be loaded even after I had fired it twice.  It is fun to keep the enemy at bay by brandishing an empty gun.
Our answer to the BAR (Browning automatic rifle).  With a little practice you can tick off single shots, a bust of two or three, or spray-and-pray all of them at once, as seen in bad TV plots.
The rifle is a common 1" board with notches (A) made with two saw cuts and the divot broken out.  Notches have to be farther apart than the length of the notch or the wrong piece will break out.  The rip cord (B) is fastened in front of the front notch with a big thumb tack or small nail (C).  A flat boot lace makes a perfect cord, although any kind of cord or twine can be used.  It should be carefully centered under each loaded rubber to prevent misfires.  The muzzle (D) is wide and deep enough to accommodate all the rubber that will be stretched over it.  Projectiles must be a looped at both ends (unlike for pistol where one end can be open).  Works most effectively if projectile lengths are customized to fit notch position, longer for the rear notches.  Rubbers can be knotted for ballistic efficiency, but a full loading bulges somewhat.
In use, the front notch is loaded first, etc.  This is not a shoulder weapon the butt of the piece is tucked in the arm pit to brace it against the vicious recoil.
A rubber gun can reliably hit an enemy Munchkin at 10-15 foot.  Maximum range is 25-30 foot or more, depending on how tightly the projectile is loaded and its air resistance.  Group size is 6" at short distance and perhaps 12" or more at longest range.  Because of their design, rubber guns throw projectiles in an arc above the barrel line.  The shootist becomes quite good at instinct shooting and deliberate point-shooting, without the use of sights.  The device is deadly on house flies, but  Mama will soon get sick of the unsightly smears on walls, ceilings, and kitchen fixtures.
The official uniform is bib overalls with (weather permitting) no underwear, no shirt, and barefoot.  Visualize Arnold Swarzeneger, Sylvester Stallone, and Bruce Willis in guerrilla jungle-warfare regalia, shrunk to three foot tall that's the way we envisioned ourselves.  Equipment (as available) :
1.  plastic helmet.
2.  genuine U.S. issue, helmet liner (always too large).
3.  leather aviators helmet complete with ear flaps and goggles.
4.  small wooden shield.
5.  rifle, bulging with knotted rubbers, slung over shoulder.
6.  brace of pistols, loaded, stuck in overall openings at waist.
7.  emergency hide-out pistol in rear pocket.
8.  bundles of inner-tube rubbers, hanging wherever
     (appearance of a gillie suit).
(established by the Grenola Convention)
A hit anywhere on the person or clothing of a Jap, Nazi, or Wop constitutes a "kill".  This depends a lot on the honor system.  There are no pussy-wimp sanctions for prisoners . . . in fact, there is no such thing as a prisoner.  The enemy's rubbers can be reused but you can't loot a dead guy's equipment or ammo he will need them when he comes back to life for a new combat.  Forts can be constructed as a stationary shield and home base.  Mobile shields made of chicken wire are disallowed because of their effectiveness.  A sacred object, in the possession of one team, can be designated as the goal of conquest.  Girls passing through the war zone may be blasted mercilessly by both sides.  Adults may NOT be shot and sometimes serve as a living shield for a raider.  A truce is called or a tie declared if everyone has to go home for supper.
The sling shot is an effective missile weapon on small animals and birds out to 25 yards.  It is accurate and becomes better with practice.
The basic -Y shape can be cut from a suitably shaped bush or tree branch.  The more symmetrical, the better.  The tines (A) are about 3/4" diameter, strong enough to withstand heavy pull.  The handle is ideally larger, maybe 1" diameter, to provide a firm grip.  The elastic strap (B) is a strip of inner-tube rubber 10-12" long.  Surgical rubber tubing is the best strap material but expensive.  The wider the strap, the harder to pull and the more power generated.
One end is bound to a tine by wrapping (C) with strong string.  The orientation is fore/aft the strap faces away from the user and is pulled back between the tines to draw and shoot.  This is most accurate and puts less stress on the binding.  Before tying the strap to the opposite time, thread it through the slots (E) of the cup (D).  Needless to say, the strap is on the back side, toward the user.  The cup is flexible leather or two to three layers of heavy canvas.  The slots should be cut cleanly (razor blade) so they won't tear out.
You can cast pebbles or peanuts for plinking or hunting, but the best accuracy is with glass marbles because of their perfect shape.  Unfortunately, kids can't afford to throw marbles away.  Nor can they afford ballistically-ideal bullets ;  36 or 45 caliber, lead, musket balls.
(10-02 Bill F.)