how much power is enough

[doyenofcastle]

Hi everyone ,
I was wonder how much power is enough for wood speargun with specific shaft dia and length ,enough to penetrate at 6 m /4 inch thick fish ,for example my 130 gun can do that at 7mm spear 170cm /2*16.6mm rubber/315% elongation ,how about 7mm spear 150 cm ?or 6.75mm spear 120 cm ? Is there a formula or something can be used for that ?

 

[Shotmaster]

I have a alemanni Mediterrano 105 that will do that. Double Rollergun. It is also accurate, I will shoot inside a 2 inch circle at 5 meters. It does drop a bit at 6 meters, 5 cm drop.

 

[DTKreten]

Hi everyone ,
I was wonder how much power is enough for wood speargun with specific shaft dia and length ,enough to penetrate at 6 m /4 inch thick fish ,for example my 130 gun can do that at 7mm spear 170cm /2*16.6mm rubber/315% elongation ,how about 7mm spear 150 cm ?or 6.75mm spear 120 cm ? Is there a formula or something can be used for that ?

Well, just about any man who tried to construct a speargun would like to know that formula. The fact is, from my expirience, power is not even the issue here. More so, i think that too much power quickly backfires. The exact ammounts could probably be calculated, though with the ammount of variables in question its just easier to toy around with rubber for one day and find the optimum. What you really are looking for are ways to redistribute the power output so that it is more gradual, preventing shaft flex and gaining more acceleration over time. It all comes down to what you are really trying to achieve, what kind of speargun would you use