Band Thickness/Diameter for Multi-Band Guns

[BoltSnap]

Do bands have to have the same thickness/diameter in multi-band guns or can one mix different diameter bands in one gun (for example a gun that can take 3 bands one uses 2 X 16mm bands and 1 X 14mm or any other combination)? Would mixing different diameter bands in the same gun cause any issues of any type?

 

[Johnoly]

..Would mixing different diameter bands in the same gun cause any issues of any type?

2 part answer.........
Mixing different thickness's (or even lengths) is a common practice for "close to bottom" hunting. For example on my suitcase JBL knock-down gun I have 3/4 and 9/16 band and also 2 different lengths. By loading only the 9/16 soft band I can get into a rocked up fish and not destroy my shaft tip with too much power. But I can also load both bands for full power and have enough punch for a mid water fish.

The 2nd part of the answer deals with "consistency". On my every day normal Koah gun my 2 bands are both 9/16 and are very exact lengths that I cut and tie myself. I change these band out every 4 months even though they are not broken or cracked. After diving every week and multiple loadings, the range and most importantly the stone shot accuracy begins to degrade. Bands are cheap, losing a $150 fish on a crappy shot is not. A chef will not serve a filet with a hole in the middle of it, accuracy is everything.

In short, try different types of setups for your gun. If you like the results STICK WITH THEM. If your accuracy is terrible, don't prolong the pain, change your setup immediately. When your gun is dialed in, your confidence will be so high that you will never miss another shot because you know exactly when your gun can't hit it and won't pull the trigger. You spend so much money just to get to the dive spot, don't go cheap on $12 of rubber.
Test > Change > Dial it in.

 

[BoltSnap]

2 part answer.........
Mixing different thickness's (or even lengths) is a common practice for "close to bottom" hunting. For example on my suitcase JBL knock-down gun I have 3/4 and 9/16 band and also 2 different lengths. By loading only the 9/16 soft band I can get into a rocked up fish and not destroy my shaft tip with too much power. But I can also load both bands for full power and have enough punch for a mid water fish.

The 2nd part of the answer deals with "consistency". On my every day normal Koah gun my 2 bands are both 9/16 and are very exact lengths that I cut and tie myself. I change these band out every 4 months even though they are not broken or cracked. After diving every week and multiple loadings, the range and most importantly the stone shot accuracy begins to degrade. Bands are cheap, losing a $150 fish on a crappy shot is not. A chef will not serve a filet with a hole in the middle of it, accuracy is everything.

In short, try different types of setups for your gun. If you like the results STICK WITH THEM. If your accuracy is terrible, don't prolong the pain, change your setup immediately. When your gun is dialed in, your confidence will be so high that you will never miss another shot because you know exactly when your gun can't hit it and won't pull the trigger. You spend so much money just to get to the dive spot, don't go cheap on $12 of rubber.
Test > Change > Dial it in.

So there is no inherent problem with mixing different diameter bands on the same gun and using all of these different diameter bands at the same time?

 

[Johnoly]

So there is no inherent problem with mixing different diameter bands on the same gun and using all of these different diameter bands at the same time?

There is no Safety problem using different diameter bands (assuming your trigger mech is quality and the sear not worn out causing a misfire). But in a normal 2 or 3 band gun and the band stretch is 300% of normal resting band length, different band diameters should not have an operational problem on a standard gun. Mixing diameters and lengths is a common practice with many spearos. Many guns are sold brand new with different diameter and length bands right off the shelf.

 

[BoltSnap]

There is no Safety problem using different diameter bands (assuming your trigger mech is quality and the sear not worn out causing a misfire). But in a normal 2 or 3 band gun and the band stretch is 300% of normal resting band length, different band diameters should not have an operational problem on a standard gun. Mixing diameters and lengths is a common practice with many spearos. Many guns are sold brand new with different diameter and length bands right off the shelf.

THANK YOU!!!

 

[STB]

There is no Safety problem using different diameter bands (assuming your trigger mech is quality and the sear not worn out causing a misfire). But in a normal 2 or 3 band gun and the band stretch is 300% of normal resting band length, different band diameters should not have an operational problem on a standard gun. Mixing diameters and lengths is a common practice with many spearos. Many guns are sold brand new with different diameter and length bands right off the shelf.

I'm redoing the 2 premade JBL blue slings both where same length 24" on my 41" JBL rail gun.

using 5/8 rubber, I cut 4' in half so 2x 24" bands.

you suggest fine tuning of bands thickness & lengths, even before reading you're advice
I was actually planning to make the first (short) band 1/2" shorter than second band by shoving 1/4" rubber though wishbone on each side.

like is there a rule of thumb crunching # lengths?STB

 

[Johnoly]

I'm redoing the 2 premade JBL blue slings both where same length 24" on my 41" JBL rail gun......

Just my opinion,,,,,If the 41" is the exact length between the band hole in the muzzle to the loading notch/shaft-fin, then 24 inch bands are a great starting point for 5/8" thick bands. Since the bands are new and harder to stretch you may find this band length is easy to load. Take a couple of shots underwater with it. If you feel like it's 'too easy' to load and you want more power, then it's easy to cut one inch off at a time, then retie the band and try it again. Normally on that muzzle hole to shaft loading point I see 22 inch bands for 9/16" thickness sold on most guns when new, so your measurement with even thicker bands is pretty close.

 

[MAKO Spearguns]

One method, BEFORE you cut the latex is to run the long piece of rubber through the muzzle, grab one end of the latex and grab in the middle of the latex and just pull back on the band (as if you were loading the gun) so that it will be close to the notch without struggling or feeling like the band is going to break. This will give you a rough estimate of how long to make the bands.

Remember, if you cut them too long, you can always shorten the latex and re-tie one side, but if you make the band too short to load, it will have no utility.

A much more objective or precise method is to cut the latex so that it has to stretch to about 340% of its relaxed length. You can measure the distance from the muzzle to a particular notch. Multiply this distance by two to account for each side of the band and then divide the value by around 3.4. That is roughly the length of the relaxed latex. The length of the spear bridles (wishbones) adds a little variability, but these two methods should come into fairly close agreement.

If you examine the tabulated data that we provide for our guns - which includes the barrel length and our band lengths, you can also get another "sanity check". For the MAKO guns, the barrel length (which is tabulated for each gun size we sell) is pretty close to the distance from the muzzle to the notch. I can't give you exact numbers for your jbl, since that is a competitor's product and I can't generate actual dimensions.

A fourth check might be to consider that the old bands were probably in the right ballpark for length, so your custom ones will probably be close.

https://www.makospearguns.com/Predator-Pro-3rd-Generation-Speargun-p/mpp3gr.htm

thanks
dano