2 homemade rollerguns

[CCspearo]

Hi guys and gals
I have just completed 2 new 110cm rollerguns. One a euro style gun using a mares trigger mech a the other a Aussie style using a seahornet mech, one for me and the other for a dive buddy. Both these guns have the shooting line release under the gun so the line does not interfere with the rollers. I have added a couple of innovations. One is a system which prevents the shooting line being grabbed by the bridle/whishbone. It consists of a groove in the gun just before the bridle catcher and a clip to keep the line off the rail area. The other is a 25mm section of partially enclosed track on the roller head. This gives the advantages of an open muzzle without the hassle of having to use the shooting line to hold the spear down.

 

[CCspearo]

The euro gun has a el cheapo $7 chinese reel it only holds about 8 metres of 1mm dyneema with the double wrap of shooting line I have about 12 metres which should be enough for me as 10m is about my maximum depth these days. I expect the reel might fail if hit a 30kg fish without stoning it. But the reel can't fit through the line guide on the front
of the gun so I should still stay attached. It really just there incase my spear gets snagged I can still surface with my gun.
below is my anti grab setup and my part enclosed track.

 

[CCspearo]

Both guns are fitted with 2/500 x 16mm rubbers which is probably the maximum the mares trigger mech will take I replaced the cast aluminium trigger with a stainless steel one I made but the body of the trigger mech is aluminium.
On the Aussie gun the only original parts are the plastic(abs) handle and the sear an trigger. I replaced the plastic trigger mech with a stainless steel one I made myself. This gun has the potential to be a very powerful weapon. The rollers are designed to take up to 20mm rubbers and there is provision for a 20mm helper rubber. Set up like that this gun capable of stoning a large marlin or yellowfin tuna. Or with a 16mm rubber it is great for general reef diving.

 

[CamboRambo]

Lovely guns @CCspearo , you seem to know what you're doing with rollers so I have a quick question if you wouldn't mind..
I have an Omer Cayman ET 105 roller with 18mm rubbers. I currently have them on the middle notch underneath the gun and when they reach the front of the gun after firing the wishbone isn't pulled tightly against the muzzle. Roughly 2cm of rubber and the wishbone is still above the muzzle.
I am constantly shooting low, do you think this could be related to the rear of the spear being flicked up as the rubbers reach the front of the gun and the wishbone isn't pulled down tightly but rather goes up. This would send the front of the spear downward. Haven't had chance to test yet but this is my theory. Any experience with this issue?
Thanks in advance!

 

[CCspearo]

Here are some more specs. The Aussie style gun has a single piece Queensland Maple barrel which has been seasoning in my garage for 20 years the butt is western red cedar with a hatch pattern on the end for grip. The 8mm stainless steel spear runs in a 7mm deep groove to prevent shaft whip. The spear has an intermediate shark fin 200mm from the back fin. you hip load to the first fin then chest load to the back fin this saves the need for a load assist seen in other guns. You can also leave the rubber on the intermediate fin for shooting in caves and under ledges. It has 2 pretensioning pins on the underside giving power settings of 280% 320% and 380% rubber stretch. The wishbones are 3mm 490kg breaking strain spectra and th shooting line is 2 wraps of 2mm 290kg breaking strain spectra. The rollers are 38mm diameter by 20mm wide self lubricating Acetal copolymer on a 8mm stainless steel axel. I turn the rollers up on a small drill press on its side to form a lathe. The roller head is made of 1.8mm sheet 316 stainless steel and 5mm round bar. It has a 5mm x 70mm shark spike to keep those blighters away when you have fish on the spear. All the stainless is blacked by setting fire to it in a tin of sump oil. This prevents sharks being attracted to a shiny gun. I have had smaller fish trying to bite a shiny flopper on my spear ruining my shot on a larger one. I have been spear fishing for over 50 years and using rollerguns for about 10 years they are so much better than standard guns in terms of adjustability, recoil, range and accuracy. I wish they were around when I was younger. Who said you can't teach an old dog new tricks!

Lovely guns @CCspearo , you seem to know what you're doing with rollers so I have a quick question if you wouldn't mind..
I have an Omer Cayman ET 105 roller with 18mm rubbers. I currently have them on the middle notch underneath the gun and when they reach the front of the gun after firing the wishbone isn't pulled tightly against the muzzle. Roughly 2cm of rubber and the wishbone is still above the muzzle.
I am constantly shooting low, do you think this could be related to the rear of the spear being flicked up as the rubbers reach the front of the gun and the wishbone isn't pulled down tightly but rather goes up. This would send the front of the spear downward. Haven't had chance to test yet but this is my theory. Any experience with this issue?
Thanks in advance!

maybe you should try shooting the gun on a stronger setting and see if that helps. if the gun fires straight and you want to use less power you could try moving the anchor point or shortening the rubbers to get enough pretension for the wish bone to finish on the catcher. The funny thing is when I first started using rollers I thought they were firing high because after years of using conventional guns I was allowing for the spear dropping over distance. Too much hook on a shark fin can sometimes cause the spear to drop as they lift the end of the spear. I don't like stops with a gradual slope for that reason.

 

[burjegol]

Lovely guns @CCspearo , you seem to know what you're doing with rollers so I have a quick question if you wouldn't mind..
I have an Omer Cayman ET 105 roller with 18mm rubbers. I currently have them on the middle notch underneath the gun and when they reach the front of the gun after firing the wishbone isn't pulled tightly against the muzzle. Roughly 2cm of rubber and the wishbone is still above the muzzle.
I am constantly shooting low, do you think this could be related to the rear of the spear being flicked up as the rubbers reach the front of the gun and the wishbone isn't pulled down tightly but rather goes up. This would send the front of the spear downward. Haven't had chance to test yet but this is my theory. Any experience with this issue?
Thanks in advance!

In that case, methink you lack the required pre-tensioning. IN my set-up, I do give about roughly 10-15 pre-tensioning of the rubber. Haven't any experience of shooting low. Could it be the effect of driving force given by the rubber vs weight of the spear x distance?
I also have a home made roller gun and inverse roller set up. Though I find the inverse roller set up cumbersome in reloading, yet it is being made up by the force and accuracy.
Most of the time, though, I am using a Mares 90 Pro Sniper, single band or the Cyrano 90 pneumatic. It is enough for taking care of Dusky groupers, amberjacks, Dentex and for a challenge, I do sometimes fast moving blue runners.