JBL underperforming, maybe bands?

[nicksh]

So I just bought a used JBL Explorer 20 for shooting in extremely low vis (3-6 feet) around jetties/pilings etc. It comes new with one band but I got it with two. I know this gun isn't that good, but I expected better.

I went to test it out in the pool and it seemed to be severely underperfoming. I set up a water bottle to shoot that my pole spear ususally demolishes and the gun couldn't even penetrate it from 5 feet away with one band, and barely with two. I had to get within 3-4 feet to do any damage (it wasn't a thick water bottle or anything).

The bands are 1/2" so I will definitely upgrade to 9/16" but I also think the guy who sold it to me (he never used these new bands) bought the wrong size. The length of the rubber on one measures 16.25" and the length of rubber on the other measures 15". I believe these are the generic 1/2" JBL bands, and I also believe the Explorer 20 is supposed to be used with 14" bands.

Two questions: A. is this the possible source of underperformance, B. are you supposed to have a slightly longer band on the outside than on the inside like the two I mentioned?

Any help figuring out the problem will be greatly appreciated!

[Erik]

If you have the black rubber bands, the no matter what you do, I'd say upgrade to latex bands.
Cheers,
Erik

[liberte]

i think the band lengths should be the same. they might be too big, i use 15" bands on a 32" ab biller. i would go with smaller bands. i had some of the same dissappointment when i bought the ab biller. it came with 2 14" 9/16" bands and a really heavy double flopper spearhead. i switched that out with a single flopper and use two 15" 5/8" bands and now it works great.
good luck