beauchat setup

[lawstraljan16]

you dont have to be a fan of them to dismiss the simplicity of a single band and single wrap gun. Im not going to get into an argument here with you about it, but i was just offering my advice. You measured in cm while i did mine in inches. that might be confusing. But i missed that earlier....

Not dismissing your opinion mate, evrryone has preference. Im not a fan of it because as I stated, I never got the results from a single 18mm as I have from double 16mm.
Though yes, 18mm is simpler to load and less stuff to get in the way.

At the moment Im not using either anymore, Im using RoiSub's invert system which kicks ass. My 75cm invert gun gets the same distance but better accuracy than a double band 110cm gun.

 

[Mr. X]

No chance 18mm band is better than double 16mm. Much more power and distance on the shot. I use 7mm shafts though

2x16mm would normally be more powerful than 1x18mm* - we did some maths to show that in an old thread** but that doesn't necessarily mean better - not by a long chalk. If it did, everybody would use double bands and they don't - most spearos here use a single band - and with good reason.


*Also, things are rarely that simple in this ol' world. The above assumes:

- similar composition bands (i.e. material and thickness of the walls. e.g. American bulk rubber is somewhat different to most of the European screw-in bands in both regards.

- similar muzzle arrangement/band length (e.g. Rob Allen railguns are reckoned to have about an extra 10cm of rubber wrapped around the muzzle when compared to a similar sized screw-in band speargun - probably even more in many cases).

And yes, more power often "requires" (works better) with thicker (heavier) spears.


**If I recall correctly the power comparison went something like this:

2x20mm > 2x 16mm > 20mm ~= 2x14mm > 16mm > 14mm

These are rough approximations. Band diameters tend to vary in the real world (and 3/4" bands are often referred to as 20mm/19mm/18mm).

 

[Mr. X]

Re. tangling bands, that might be more common if one of the bands is a set of screw-in rubbers and/or you have one of those fancy Omer muzzle wishbones which flip over the muzzle, as optionally fitted to the Omer XXV & some Cayman models.

 

[AlexbeeintheUK]

I have the 95 and 115 Marlin (not elite, just standard aluminium barrel) with 6.5mm SS spear. They both shoot much better with double 16's versus the standard 18mm.

However, this spear is very easily overpowered so be conservative with your stretch ratios and try not to go above 3.0
Correctly made twin 16's on these Beuchat Marlins makes them so much more useful/powerful I don't know why they don't ship them like this - a 7mm SS spear would be perfect match as well!

 

[lawstraljan16]

Yeah. I had changed my spear to a 7mm with double 16mm bands to 3.2% stretch and it was great