Suggestions for zip gun?

[NickSG]

I wasnt sure whether to post here or Improvised Weapons, but ill give this place a try. If the mods feel like moving please feel free to do so.

Im planning on making a zipgun sometime before the year is up. I have the plans ready and all, but I was wondering if there is anything better than a end cap to hold the bullet in place.

The design is fairly simple. A .22LR bullet is placed in a 1/4 inch ID steel pipe (with one end threaded). A 1/2 inch ID steel end cap (assuming the walls of the pipe are 1/8 inch) is screwed on, but first, a dremel tool is used to grind away a section of the outside edge of the cap, so when screwed on the pipe, the rim of the bullet (where the primer is) is exposed. I have the firing mechanism all figured out, but I was wondering if anyone had any better ideas as to how to keep the casing from flying back after the bullet was fired. The steel cap is a good idea, but it would take too much time to unscrew it after each to shot to empty and reload, and I assume it would be difficult to make sure the grinded part of the cap always ended up in the right spot (otherwise the hammer would never hit the right spot).

I already have the blueprints drawn out, but if needed, I have some simple drawings of the gun online.

Any suggestions would be greatly appreciated.

[angelo]

yes this thread should be in the improvised weapons forum.

Thats why I moved it.

[Anthony]

You don't need to have a cut out for a hammer to hit the rim of the cartridge. You can have a normal firing pin and offset it from the centre of the end cap, so that it strikes the rim of the cartridge. The profile of the firing pin tip is important though, a normal "spike" and it'll often go right through the cartridge base without setting the round off. Making the tip into a blade shape (like a screwdriver) gave complete reliability IME.

Because you're just drilling a few mm hole in the endcap rather than grinding away a significant area of it, it should be left with a little more strength.

You could cut slots into the thread of the pipe and endcap to create an "interupted thread". You then just align the slots, push the cap onto the thread and a quarter or half turn locates the threads. Was used on the breaches of quite a few large bore, shell firing military guns.

[NickSG]

The firing pin is just a 1 inch length of 1/16 inch copper wire. Both ends are flat, but the striking force of the hammer is so great I dont think I will have any problems with firing.

Does anyone have any suggestions other than an end cap, though? I hoping for something faster than an end cap (to make it quicker to load and reload), but something a little simple. I searched the forums and found a few people who have made zip guns in the past, and im curious as to what they used to keep the casing from flying out of the barrel.

[jelly]

I remember the drawing of a unique .22-caliber "rimshot" pistol.

The body is made from three sections of wooden broomstick.
The middle section swings up for loading after the striker is drawn back.
Once loaded, the user presses the middle section closed, which aligns the
striker and fires the weapon :p

With a good technique you should be able to fire dozens of rounds per minute :D

[walbern]

You may want to check out the following thread from 2001.
Single shot gun plans
Improvised Weapons page 6
Twinkle is thread starter

[xmarinevet]

You can just order surplus flarepistols off of the net at various places for around 20 bucks. Drive a piece of 3/4 inch water pipe in the barrel and its chambered for 12 gauge really cheap to make easy to build and sell to friends.

[Ammonal]

You asked for a suggestion and the best thing that I have seen and used is the breech loading of this pistol. Although primitive and slow to reload, I have made a handgun firing a .22LR using a plate that slots down behind the cartridge, with a hole in it allowing the firing pin to strike the rim of the shell. Email me for pics (dont want to post pics of homemade handgun as Australian law would murder me :(

[A-BOMB]

To make a easy zip gun your going to need a barrel you can get them HERE (www.e-gunparts.com) and a thick steel door hinge about 1" to 1.25" wide and about .1875 to .25" thick and a spring, hammer and trigger all of which can be made rather easy. First hammer the center pin out of the hinge so you get to metal plates next put the plates together again but without the pin. Next take you hammer and cut a slot into the hinge to fit the hammer in so the pin hole in the center of you hammer First you must drill a hole in the hinge to the OD(Outer Diameter) of you barrel thats if you plan to braze/solder/weld it in the hole. Else you need to drill and tap the barrel and hinge.

I'll stop writing this now and draw up some thing to help explain.

[jelly]

I have uploaded 2 drawings of very simple pen gun principles here:

Pen Guns (http://jellybelly84.tripod.com/penguns)

The first pic shows a .22 cal pen gun made from common materials.

The second pic shows a .22 cal rimshot pen gun made from three sections of wooden broomstick.

And don't forget to take a look into the pen gun related patents I have posted
in another forum section a year ago:


Gas Pens:
1,663,834 Fountain-Pen-Shaped Pistol
1,772,070 Gas Pen
1,772,656 Gas-Cartridge-Firing Device (Gas Pen)
1,775,178 Gas Pen
1,826,562 Gas Pen
1,897,992 Disabling Gas Firing Weapon (Gas Billy)
2,757,474 Pen Type Tear Gas Gun

Bullet Pen Guns:
1,608,359 Fountain Pen Gun
1,681,172 Pen Gun
2,880,543 Pen Pistol

Squeezer Guns:
2,042,934 Squeezer Pen Gun
788,866 Squeezer Firearm

[Chemical_burn]

hmm intresting but in the pics I have noticed that it says 1/8" nipple, but that is much smaller than a .22cal round. Because .25 cal is 1/4" twice the size of 1/8". I just want to make sure its not labled wrong and to clear that up.

Also on a second note I am not %100 sure how the broom stick gun works and also how reliable is it. To me it would work but probably only once maybe twice.

[jelly]

Thanks for the hint. Maybe the draftsman has mistaken the inner diameter for the thread length.
Since there is a metallic barrel in the left part the broomstick gun shouldn't break
when firing .22 cal rounds:p

[xyz]

There is no mistake in that diagram, according to "Homemade Guns and Homemade Ammo" schedule 40 1/8" steel pipe actually has an internal diameter of .264" and an outside diameter of .405". I think that the ID of the pipe used to be 1/8" back in the day but now thinner pipe is used but the OD has remained the same so that old fittings can still be used.

Pipe sizes are always some retarded number that has nothing to do with the size that the pipe is sold as :rolleyes: .

EDIT : I would just like to add that because the ID is .264", you would be able to fire .22short, .22long, .22LR, or .22Mag all in the same gun. If you wanted a better barrel fit, you could use a .243 or .25 bullet with a .22 blank behind it. Make sure that the gun is strong though as a bigger, heavier bullet will mean higher chamber pressures

[steyr]

my friend has a gun (he received it from his grandpa) and it's very small (about 9cm). it's single-shot, and very small caliber (i don't know what caliber is this). the pistol is not zip-gun, but it can give you some ideas for it.

[Wild Catmage]

The miniflare discharger used by the UK military can easily be adapted to fire .22 rimfire rounds. Because of this, the civilian version is slightly different in design, although military ones are available from certain sources (I'll try and find more info on this topic). 21/11/2003