Standardized speargun test

[Kodama]

I have been trying to inform myself about speargun physics and follow several treads on the subject. A lot of spearos have been testing a lot of different setups.
Has there been a consensus on a standardized speargun test? As for as I know not really.
I think the community could benefit from such a standard. Could we figure out what this should be?
What are the prerequisites?


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[Pinniped72]

As far as I am aware the only thing about spearguns that has been thoroughly researched is the draw strength of the rubber used, there are tables available for the various diameters and stretch ratios with the load in Kg's and pounds. I guess we would need to decide what we are actually trying to get results for, accuracy, water resistance to lateral and vertical movement for use in strong tidal water, balance, maximum spear weight, diameter and length, maximum load on the trigger mechanism are a few I can think of. For me personally the more information that manufacturers can supply the better, the same goes for all our other gear, fins, masks etc.

 

[Kodama]

What would be most important is accuracy, range, trajectory and impact force.


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[Bill McIntyre]

The most extensive tests that I know of are done by majdq8. Search for his youtube videos.

 

[Kodama]

I am well aware of his work and also looked at the VideOcean crew. It is because of their methods that I bring up the subject. And as they have mentioned themselves if the community doesn't agree on a standard for testing speargun ballistics we just keep comparing apples with melons.


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[Bill McIntyre]

I seriously doubt that the community could ever agree on a standard, and I'm not even sure it would be desirable. Could we have a single standard that compared pneumatic guns and band guns, or 75 cm rail guns to tuna guns?

From what I've seen, Majd is the g0ld standard. He moves the target one meter at a time and we see the shot at each range. We see how penetration and accuracy varies. He keeps the shaft constant and changes band types and thicknesses. Or he keeps the bands constant and changes thickness of shafts. Most recently he kept the gun, shaft and bands constant and tested various shooting lines to see how accuracy and penetration varied. That was of great interest to me. How could we impose a similar standard for everyone? Who would be willing to do the work?

While his videos are the same wherever we see them, his text comments and the comments of others may vary. I see him on Spearboard, and I don't see any serious complaints with his methods. Those who do quibble also happen to be speargun manufacturers, but they may have an axe to grind. I've seen them offer a view of a single shot in a pool. It always hits the target, but we don't know how many other shots missed, where the aim point was, or even the distance. Or they may offer a video of a customer shooting a tuna with their guns. I'm sure the tuna was actually shot, but many guns shoot tuna. That doesn't constitute a standardized test that can be compared with other guns that take tuna.

Majd often seems to go where his results lead him. He suspects that the gun might do better with a lighter shaft or heavier shaft, so he tries it. Or in the case of one gun that I own, he added one more band to see if that improved range, and found that range and accuracy suffered. That save me the trouble of trying one more band myself, and never being quite sure why I was missing.

But there are so many variables that could change, and I don't think we could ever impose a standard that would cover them. I'd prefer that the guy doing the tests explain what he is doing and why, and let me evaluate how much weight to assign.