make it yourself single use powerhead

[MATTKINZ]

these are pics of disposable single use powerheads made of steel pipe crimped on 357 magnum cartridges or M16 bullets. They are for spearfishing protection against sharks ( It is illegal to spearfish in florida with powerheads though they may be used for protection).

When one of my dive buddies was harrassed significantly by a bull shark, I embarked on this project. Local dive stores sold a "limited use powerhead" and another diver published a drawing of a pvc tube version. These are my version of the same thing. They are made of 16 gauge steel tube from a hardware store. Once assembled, they are painted with cold galvanizing paint to prevent rusting and then aluminum paint.

The bullets are crimped into the steel pipe sleeves, a spacer centers the tip of the spearpoint on the primer in the firing position . A larger piece of plastic tube holds the assembly and slides over the barbs of the point with good friction fit. For another , larger spearpoint, the spacer isn't needed.

some of the pipes are longer, these contain M16 223 cal rounds. The short ones contain 357 magnum hollow points.

1 picture shows the spearpoint slid into place in the firing position.

another pic shows bullet embedded in a 2X6 piece of lumber.

 

[CON8IV]

Wow! I'm not sure what to make of this. I'm all for spearfishing and a handloader as well. Seeing as the 5.56mm NATO, or .223 Rem cartridge can generate over 51,000 CUP, I would be hesitant to use this one. And, did the person who made these actually put the .223 cartridge in PVC tube ONLY? Although I've never used powerheads myself, it seems that you would end up with an exploding case where the .223 is concerned as it is tapered, and would not contact the pipe/tubing over the entire length of the case.

Also, do you guys who frequently use powerheads seal the front of the "muzzle" with tape or something, or put clear nail polish around the crimp to prevent water from possibly reaching the powder? I've always been curious about powerheads. From what I've heard they are quite fun to use.

 

[D1V3R]

Since when is it illegal to use power-heads in florida
I used to use 9mm powerheads offshore jacksonville all the time until a couple years ago when I switched back to conventional spears for saftey reasons

 

[Scubakevdm]

November 26, 1992. I think. Here's a link to the statue.

 

[D1V3R]

awwwwwww, that sucks
well, I wasnt planning on using power-heads anyway

like I always said "If its too big to be killed with a spear, It doesnt need to be killed"

 

[Johnoly]

Not sure I'd like to see firing result. The main effect from a powerhead is not the bullet, but rather the gas expansion and hopefully it's forward direction. For that reason I'd go with the 223 not the 357.

Forget that the jacket and primer may not be sealed, but the extended length of the tube past the bullet would probably splinter, the direction unknown. I can't see if the bullet is removable or if the tube must also be replaced after each dive, but at 120 feet, that bullet/primer is probably going to leak and the powder get wet inside.

One other consideration is that if the spear tip is in direct contact with the primer, it has very good chance of pre-detention with a very sharp tip and 3 bands loaded. For his individual setup, it may protect him just fine, but I wouldn't use it across gun platforms. Most PPD's are used at very close range with minimal or no distance to launch an offensive.

FYI, My PPD's are only for personal protection, not hunting.

 

[JustinW]

Hurry, if you use this by the end of the year you won't miss the nomination deadline for ..... http://www.darwinawards.com/

 

[Wayward Son]

Dunno what your cost in time & materials on this is, but you can buy a resuable slip on powerhead for $30.

 

[Don Learn]

We hunt with powerheads exclusively off shore Jacksonville. If you read the law carefully, you will see it refers to state waters. They really should clarify this in regaurds to fishing. State waters are lakes, rivers and inland tributaries. State waters law enforcement can also enforce their laws up to 12 miles off-shore. If you really want to research it, you will find it is actually illegal to spearfish with a powerhead within 3 miles of the coast. This can be found in some of the commercial laws that also apply to recreational taking of fish. Hope this helps clear it up.

 

[MATTKINZ]

reply to con8IV
I tried PVC with a surround of larger PVC , it exploded.

With the steel tube, the end of the cartridge does expand and gases blow by, however it sinks the bullet into a 2X4 pretty well and punches through 1 inch deck boards well, plenty of power for what you might need. Actually, years ago someone sold a shark dart that was a hypodermic attached to a big CO2 cartridge that would give a shark an air embolism. I would think one would be subsonic on the bullet but put a fair amt of hot gases into the fish. I haven't had the chance to use while diving, a lot of rounds were fired in a lake and none of the steel tubes blew.