13 vs 16 vs 19 rubbers

[vjanda]

Hello all !

I came across this interesting chart that compares effective shooting range of spearguns with different rubber bands :

http://www.beuchat.fr/img_catalogue/fr/_photo_030206170201.jpg


I'm a bit puzzled to see they think a 100cm gun with 13mm bands will outshoot a 90cm with 16mm bands.


I've always been intrigued in ballistics :martial so was wondering if you think the chart is reasonably accurate?

Cheers:friday

 

[Rogert]

thats pretty interesting but i always though that a 130cm gun with 18 bands would go further than 4.30m

 

[Huw]

thats pretty interesting but i always though that a 130cm gun with 18 bands would go further than 4.30m

Indeed the spear would go ALOT further, however, the graph shows effective shooting distance, meaning accuracy - and above all a reasonable level of penetration of the target... often being a muscular pelagic for a 130cm gun with 18mm bands. I would say that that graph is a rough guide, but provides a reasonable prediction to an issue that has so many variables.

Huw.

 

[deep thinker]

I agree with Huw, its a rough guide showing effective distance before the spear starts to 'fall'. You could still hit a target at that distance or further but the velocity of the spear will have deteriorated by then. Another thing to consider would be the diam of the spear you use, fresh and saltwater but the water types mite have a minimal effect allthough still a effect due to resistance factors saltwater being 'heavier' and also the age of the bands. Its a good guide though and can be used to assess a situation and to help you learn the extremities of your gun with different band types etc

 

[marginatus]

http://forums.deeperblue.net/631737-post6.html ??
Can some of you help on this?

 

[deep thinker]

Id say youd be hitting in 5 to 5.5m range, but for that I mite opt for twin 18s rather than 16mm bands. Just to add punch to the range, with a 8mm spear and the reinforced carbon barrels with track on the apex it wont be easy to overpower the gun.

 

[fuzz]

I noticed that they also differentiate between different guns.

Perhaps these charts take into consideration different shafts used in different models as well?


Thanks for the chart - cool stuff.

 

[Mr. X]

I noticed that they also differentiate between different guns.

Perhaps these charts take into consideration different shafts used in different models as well?

That would make sense. I suspect these are intended for marketing purposes, to differentiate different products in the product line, rather than actual measured results. If the results were measured you might get some undesirable "cheap gun shoot further than expensive gun" results (e.g. if they used a thinner spear perhaps).

BTW the spear will start dropping as soon as it leaves the gun (gravity) - in a parabola, the diagram gives some sense of that. The drop will accelerate under gravity & so becomes more noticeable as time goes on, and as the spear slows down (less horizontal movement).