Speardiver Quick slip-on Powerhead and belt pouch

This Speardiver Quick Slip-on Power Head is designed to be used as shark defense. It is a slip on single use powerhead made of aluminum containing a sealed in 7.62 X 39 Remington 145 grain round (AK-47 round). This power head is spear actuated, there is no moving firing pin and as such it is legal to carry on one's person or in the car. The powerhead is deployed when the tip of the spear strikes the primer through a water tight seal on impact with the shark. The spear hole is machined with very little tolerance and as such does not allow play when the shaft is fired from the speargun. Common misfiring which is due to the spear point striking off the primer is non existent. Comes in different diameters to fit 9/32(7mm), 7.5mm, or 5/16(8mm) shafts and can be made custom to fit larger diameters as well. The neoprene Speardiver Powerhead Belt Pouch holds two powerheads.

Features
- Very powerful round is enough to kill shark depending on shot placement or at minimum severely wound it to the point of discouraging it from returning.
- Very quick to mount on spear, especially if used with belt pouch
- Sharp edge on the front end helps it catch on the shark on angled shots.
- Built in O ring for snug fit. The powerhead seats tightly enough on spear that if target is missed the powerhead will not come off due to inertia when the spear is stopped short by the shooting line.
- Machined grooves provide grip when mounting on spear with bulky gloves.
- Water escape hole for easy insertion of the spear.
- Completely waterproof, the round is sealed inside on both ends and as such requires no maintenance.

The PH are coated with a clear coating. This will keep them looking shiny and new, aluminum will normally look dull grey in color after exposure to salt water. You may even toss the PH and let it fall through the water to flash in that big one that just won't come close

I know from personal experience and have received feedback from many others that the common reloadable powerheads which use the little piece of rubber hose to retain the round consistently fail to deploy. This occurs due to the spear point striking off the primer. Water resistance/drag on the PH as the shaft is fired exerts enough force to displace the spear point as the rubber piece does not hold it firmly enough. It is easy to see upon inspection of the round that misfired. There will be a dent outside the firing area. A machined aluminum PH with very close tolerance to the diameter of the shaft does not allow this to happen. The spear point strikes in the same spot every time. For this design to work the round must be inserted from the front. In this case there is no way to keep it in place but with epoxy. This makes a reloadable powerhead not feasible for this application. I suggest to those of you who own a reloadable powerhead to test it before you need it. While there is a comfort element in assuming you are protected, I personally would rather know than guess and would be willing to invest the cost of a round and a little time to find out.

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I gather you have had them crack on you?, Are these PHs heat treated, Aluminum? or just machined? Does this device come with instructions on how to reload it, epoxy and all?

I have not had one crack on me but I was told that they can crack by the manufacturer. I don't know what factors will make it crack on one occasion and not on another, nor do I know what percentage of the time it will go one way or the other. They are made of aluminium which theoretically is not made to withstand repeated firing of a cartridge. When I first walked into a gun store to buy ammo for a reloadable aluminum PH the store owner who was a ballistics expert said he would not expect the PH to stay intact. I realize that this may not be the case all the time but you must admit rifles or pistols are not commonly made from aluminum. One might argue that the physics of firing underwater are different, I do not have the knowledge to say yes or no to that.

Reloading is possible if the casing is not stuck in the PH after firing it. It requires cleaning out the cavity well, inserting a new round and sealing it. Epoxy is used to seal the front of the PH. Soft sealant is used to seal the back that comes in contact with the spear point. The spear point has no problem penetrating this.

As far as making the PH reloadable. First, I'm sure you're aware that companies such as Beco make a very reliable reloadable PH. The question is why is such a PH not suitable for us as spearfishers for shark protection, there are a few reasons.

1. They take too long to put on, secure in place and remove one or more safeties in a tense situation.
2. For a consistently effective caliber cartridge the stainless steel PH would have to be too heavy to allow reasonable range when mounted on a speargun shaft.
3. They can be deployed by accident, such as by dropping them.
4. Not a very important reason but nevertheless; The legality of moving one around on land is questionable.

An aluminum PH solves the problem of weight and range while allowing for a powerful cartridge. The single use design makes it compact and further increases range while at the same time eliminating all risk of accidental discharge and any legality issues.

If the aluminum PH were to be manufactured to allow reloading, cost would increase while the probability of rendering it useless after discharging will stay the same, not a good deal.

There is a combination of factors here that make the status quo the best solution.

You do realize that they are single use? In this case why would you prefer a .223 to the much more powerful AK47 round? In the near future I will stock quality Beco style reloadable power heads at a better price than Beco. These ones will take .357 and .223 rounds. But I don't recommend them for shark defense which is what the ones in this thread are for.

I understand your reasoning. This powerhead comes with the round sealed in so there's not a concern of sourcing out the AK47 cartridge. I say this again to clear it up for someone reading this and getting the wrong idea.

I have no compassion for sharks that pose a risk to me or my catch. They're capable of a "thought" process that allows them to respect a bigger shark that can be a danger to them. If they're not doing the same thing with me it's because I've become a "non threat" which is not far from prey. I can't allow this to happen.