Speargun Target Material

[Grizzlestomp]

I'm getting ready to try out my new double roller in the pool and decide between a 5/16 and 11/32 shaft.

Anyone have some advice on the best material to make a target out of? Want something with enough density so that the spear doesn't fly clean through.

Thanks

[diveincanada]

I use the cover of a big plastic bucket

[kwtony]

If you are using a friends pool or even sneaking into a nearby hotel at midnight, i find that its perfectly fine to use an actual fish. It really gives you a good idea of just how well the spear impacts on a real world level. Most of the time there isnt much left to clean up so its kind of a win win....be sure to post photos!!!

[CuzzA]

Get a 13 gallon garbage can, draw a target on it and weight it down with some lead. Roll up some strips of old carpet and stuff it in the can.

You may or may not want to remove the flopper though as the shaft could get stuck.

[freediver4life]

Duct tape couple of old boogie boards together 👍

[deanmc]

I use Kickboards that you can buy at a local pool supply store. Only takes about 10lbs of lead to hold one underwater.

[Blue2u]

Kickboards single or doublel, I tape my flopper once my shots are dialed in I untape it

[popgun pete]

Anybody try ballistic gel? I suppose the mass of a spear shaft might push right through it, but it can certainly stop a bullet with high velocity as it plows through the gel leaving a track. I have never handled the stuff and only seen it on TV whenever there is some discussion about high power weapons and what damage they can deliver to a human being or animal.

[Chuuken]

I have never handled Ballistic Gel, but I know there are plenty of "DIY" videos for making it on YouTube. Two things immediately come to mind:

1) How does Ballistic Gel hold up underwater?
It could be an interesting experiment. Or, it could be 10 pounds of ick on
a stick.

2) I would look to archery targets more than firearm targets.
When I took hunters safety (so long ago), they did a demonstration to get us to respect Bows. If you ever see a class of new hunters, it's pretty reliable that everyone gets all reverent and careful when the deer rifle comes out, but it's a more relaxed, casual feeling when it's a bow.
The demo is just shooting a sandbag. you put a half dollar sized dot on a sandbag so you have something to shoot at, then you shoot it with a 30-06 or whatever. The sand stops the bullet. our bag couldn't have been more than 4" thick, bullet stays in bag. Then you shoot it with a broadhead. The arrow reliably gets stuck by its fletching as it pins the sandbag to whatever is behind it. Simple machines are scary.

so, all that anecdote is to say; I'd try to sink an archery target. Imagine shooting at a foam deer underwater.

[spearq8]

For simple accuracy testing you can just use 5cm XPS construction foam ... it holds up pretty good to repeated testing. As for penetration testing, I used an actual large King Mackerel and sacrificed it for the sake of science and used it to see what it would take to penetrate that fish with a spine shot. I conservatively came up with 2 x 5cm of 38kg/m3 XPS styroboard. I increased that to 15cm for Tuna test ... but never did actually put a tuna in the pool this time. The King Mackerel was much easier to penetrate than the 10cm of foam and probably equivalent foam is about 7cm ... but it is good to err on the conservative side. It is incredible how accurate and repeatable this penetration test is and I used it to really push the performance envelope of regular spearguns. If you have good accuracy and good penetration ... you have a good gun ... it is as simple as that.

[Behslayer]

Hi Taylor, I use either a Reel or a 1-2lb weight attached to a breakaway to make sure things don't go too far. For Target material, the most ideal is to have a Sled which holds your foam rigidly like a Frame. This is much easier to puncture than free floating foam, but gives good consistency. But the reality is that most people don't have a purpose built Metal Sled with 100lbs of weight on it. You can get Insulation Foam panels in different thickness and different density at Home Depot. But keep in mind how much weight that will need to be submerged. I've made up some really nice targets in the past only to learn I had no where's near the right amount of weight to sink them. In the end, the simplest is to take some of those foam floor tiles which you can find in most box stores https://www.walmart.com/ip/Norsk-Sto...-Pack/13253269. Bring a few weight belts of weight and some string so you can tye off to either side and have the target face you. You can use 2,3,4 if you have enough weight. 2 panels works fine. A target supported in this way has some give and will be much harder to penetrate than a rigidly held foam panel and takes a LOT less weight to sink. It kind of grabs the spear as it moves. but will give you fairly consistent results.

[popgun pete]

It may be possible to build a composite sandwich of foam blocks of construction material interleaved with sheets of thin gauge alloy and mount the sandwich in a metal frame. The frame can be disassembled to change sheets and check hole locations in the metal sheet and how many sheets were penetrated. An accuracy target can be a mesh grid of flexible material in the style of netting, the shooting line indicating which hole the spear has passed through.

When my colleague Sergiy was testing his guns he used large plastic containers such as bulk oil bottles filled with sand. The only problem was the wet sand was brushed aside and the spears flew nearly right through a stack of sand filled bottles! But then they were being driven by over 1,500 psi of pressure, and maybe even more on occasion!

[Matt Hudson]

Yoga mat

[Mike N]

I like to use plastic water bottles weighed down with lead and line. There isn't enough resistance to prevent the shaft from flying thru, but it is reusable until you penetrate the high spot and let out all the air.

MN