okay, so first of all. what is the difference between an open and closed muzzle? why is there such a price difference? and what do they do to accuracy and power? and what is bulk rubber stuff? is it just buying rubber in bulk? like by the foot. and if so, how do you put it on your gun? sorry about all of the questions. i am kind of new to the speargun thing. thanks!:t
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open muzzle vs. closed muzzle
- Thread startersoljah
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Open muzzle just gives you a cleaner aiming line, cause you have a visual perception of the shaft in all its length with no interruption. For this reason, some people say that open muzzles give guns a higher accuracy. Is it true? bah...Me I think it's just a fashion thing: newest guns are almost all with open muzzle, and this is why they are more expensive (new models have higher prices than "outfashioned" ones).
Me I've always used closed muzzles and feel no problem with accuracy. On the contrary, closed muzzle guns are faster and easier to load: unlike open muzzles, they dont' require to wrap up the shaft with the line.
--bulk rubber: you buy rubbers and cut them in the required size, instead of buying them ready made. It's a thing you can do to create your own custom circular bands, making a do-it-yourself wishbone with knots of dyneema or kevlar line. This way you save some bucks...
Me I've always used closed muzzles and feel no problem with accuracy. On the contrary, closed muzzle guns are faster and easier to load: unlike open muzzles, they dont' require to wrap up the shaft with the line.
--bulk rubber: you buy rubbers and cut them in the required size, instead of buying them ready made. It's a thing you can do to create your own custom circular bands, making a do-it-yourself wishbone with knots of dyneema or kevlar line. This way you save some bucks...
I agree with everything that spaghetti but I would add that open muzzle will give you more power.
The Open Muzzle gives you more power then the closed muzzle, in fact I was playing around in a poll with my friend. My with with my teak-sea azimuth 100 rigged with a single 19 mm (circular band) him with his Omer Master America 115 with the original omer band. Both using the same shaft, my gun had a longer shot then his.
Open muzzle -more power? maybe a little if spear is hitting closed muzzle due to some bending may have a little friction? testeing 2 different guns with different rubbers is not an accurate comparison of muzzle styles you would need exactly the same gun with only the muzzle different to be conclusive and then try over a number of shots and swap rubbers one rubber may have more elasticity than another from same manufacturere due to age,manufacturing variation and many other variables. closed muzzle faster to load ? I find open easier to get spear into mech without having to thread it through the small ring at end of muzzle just drop it on to barrel and push back last 50mm or 2" single wrap of line is almost automatic without concious effort after some practice your hand swings line around pin and end of gun then slide back to hook on line release in one fluid movement unless its tangled which happens also with closed muzzle, I have both but prefer open muzzle -only problem is in dumping surf it may come loose and line come off . this is not very common except in breaking surf.
Peter
Peter
I have open & closed muzzled guns.I think the test result is down to the fact that the master america has a standard euro rubber that pulls in line with the shaft.A circular one can also be added.The Azimuth uses circular rubbers only so you obviously have the extra rubber that comes around the front of the muzzle.Quality of the rubbers as well as thickness & thickness of shaft plus shooting line type all come into it.
I find that the open muzzle design has an annoying habit of the line coming off in surf or when its in the boat resulting in tangles.I also find it quicker to reload with the closed.This is a definite bonus when you are dropping on a shoal of fish & hope to string a few more before they move on.I dont find this so much a problem in the med where I tend to take fewer shots & have longer(generally )between dives due to deep diving.
Where open muzzzles score over closed is when using shark fin loading tabs on spears instead of notched as there is nothing for the tabs to catch on.:martial
I find that the open muzzle design has an annoying habit of the line coming off in surf or when its in the boat resulting in tangles.I also find it quicker to reload with the closed.This is a definite bonus when you are dropping on a shoal of fish & hope to string a few more before they move on.I dont find this so much a problem in the med where I tend to take fewer shots & have longer(generally )between dives due to deep diving.
Where open muzzzles score over closed is when using shark fin loading tabs on spears instead of notched as there is nothing for the tabs to catch on.:martial
There is a huge difference between closed and open muzzle as regards recoil. Closed muzzles with screw-in bands tend to go up in the moment of firing causing inaccurate shots. Eventually the mind gets used to it and fixes the errors of the gun, but according to physics open muzzle should be more accurate.
I agree on the extra power part too. It is due to the extra piece of rubber passing through the hole.
Here is some info on the recoil and on closed vs. open muzzles
http://www.dapiran.it/dapiran/tecniche/dapiran_010423.htm#TERZA_PARTE
Sorry if you don't speak Italian, but the article has some very good graphics, so you can get the idea. There are loads of other sources also in Italian, but I think Dapiran is good enough expert, so I choose to trust him
I agree on the extra power part too. It is due to the extra piece of rubber passing through the hole.
Here is some info on the recoil and on closed vs. open muzzles
http://www.dapiran.it/dapiran/tecniche/dapiran_010423.htm#TERZA_PARTE
Sorry if you don't speak Italian, but the article has some very good graphics, so you can get the idea. There are loads of other sources also in Italian, but I think Dapiran is good enough expert, so I choose to trust him
Sorry I should have sent both guns to Nasa to have the test done, spearfishing is such a precise science ! But my intent was to say the circular band adds power not the open muzzle, the master America has an Open Muzzle but with a split band. What was surprising to me was the amount of power that you gain by using a circular band. I also agree with the open muzzle being a pain on the boat.
Circular bands probably give more power than screw-in euro bands, but in many models they require a rail to be accurate, and the rail gives a bit of drag so that power diminishes...so what?
However, open muzzles do not necessarily use circular bands: the new Omer XXV shoots with open muzzle and couple of screw-in bands, same as Seatec gabbiano open and others to mention, while the sporasub instinct has a semi-open muzzle. They're "cleaner" to aim, but power is a different issue AFAIK.
---Curiosity: here in Italy the kind of muzzle with two or more holes for circular bands is called "australian". Is it really an invention of the aussies as you guys know?
However, open muzzles do not necessarily use circular bands: the new Omer XXV shoots with open muzzle and couple of screw-in bands, same as Seatec gabbiano open and others to mention, while the sporasub instinct has a semi-open muzzle. They're "cleaner" to aim, but power is a different issue AFAIK.
---Curiosity: here in Italy the kind of muzzle with two or more holes for circular bands is called "australian". Is it really an invention of the aussies as you guys know?
I'd like to chime in here too and ask a follow up (albeit maybe a stupid) question: is an enclosed track gun concidered an open mussel or closed mussel gun? Also what are the benefits for an enclosed track gun. I'm new to this whole spearfishing thing too and I really enjoy the threads I've read here. Thanks to all of you that have been sharing you knowledge for us rookies.
cadiver
You find enclosed normally in wooden guns, the function is the hold the shaft in track while the rubber is in action to try improve precision. I've only see enclosed tracks on Wooden gun or the riffe metal tech, those have open muzzle and circular bands. I picture have a 1000 words.
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You find enclosed normally in wooden guns, the function is the hold the shaft in track while the rubber is in action to try improve precision. I've only see enclosed tracks on Wooden gun or the riffe metal tech, those have open muzzle and circular bands. I picture have a 1000 words.
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What are Omer thinking of with the xxv? If your gonna have an open muzzle for better sighting why use rubbers that pull in line instead of circulars??
Interestingly Fabrizio of Totem sub guns did some tests & found that rubbers which are split/screw in still caused the spear to wobble as the spaer passes out of the trigger mech & over the guide in the middle before passing out of the muzzle.With circular bands & a rail the rubbers keep the spear on the rail & this doesnt happen.
As for the rail slowing the spear down,Rob Allen says that the spear travells on a film of water which acts as a lubricant.Either way i cant see it has a massive effect.
Interestingly Fabrizio of Totem sub guns did some tests & found that rubbers which are split/screw in still caused the spear to wobble as the spaer passes out of the trigger mech & over the guide in the middle before passing out of the muzzle.With circular bands & a rail the rubbers keep the spear on the rail & this doesnt happen.
As for the rail slowing the spear down,Rob Allen says that the spear travells on a film of water which acts as a lubricant.Either way i cant see it has a massive effect.
By chance tomorrow morning I'll go spearing with my buddy who has the Xxv gold. I'll try it and let you know my impressions. But, still talking theoretically, I don't understand Jon's objection...Open muzzle with bands in line is just one of the four options of XXV's multifunction muzzle. And then what's wrong with it? It's just about using a couple of euroslings for those who prefer them, while keeping the muzzle open for a better sight of the shaft. It's an option among others, I cant' see any conceptual contradiction in this.
---(for me the multifunction muzzle is just a "cool for cool" fashion thing. What makes the XXV Gold interesting to me is the slim 25cm barrell with integrated rail: compromise for a very handy and lightweight, but accurate gun. Let me try it tomorrow)
---(for me the multifunction muzzle is just a "cool for cool" fashion thing. What makes the XXV Gold interesting to me is the slim 25cm barrell with integrated rail: compromise for a very handy and lightweight, but accurate gun. Let me try it tomorrow)
Thanks Strangelove. I see what you mean on the Riffe Metal techs. Also looks like the Wong Bluewater guns have an enclosed track. Is there any drawbacks to having an enclosed track gun. Does it result in a louder gun (wishbones rubbing on the metal enclosure)
Cadiver
Normally the enclosed tracks I've seeing are made with delrin so there is no metal rubbing a possible draw back is if the track was not properlly installed it could come lose or detatch from the gun. For all I know derin is more slipery then wood.
My dream gun at this point would be a excalibur 3000 with a delrin enclosed track.
Normally the enclosed tracks I've seeing are made with delrin so there is no metal rubbing a possible draw back is if the track was not properlly installed it could come lose or detatch from the gun. For all I know derin is more slipery then wood.
My dream gun at this point would be a excalibur 3000 with a delrin enclosed track.
The semi closed track is a true rail. As such, no muzzle is needed, only a slot for the circular bands, or a bracket for the split bands. Thus, the sight picture is as good as any open muzzle and there is no inconvenience of having the spear come adrift during general transportation, handling or loading. There is no need to wrap the muzzle with a shooting line to control the arrow. Accuracy is good in the sense that the spear is completely controlled by the mono-rail construction. Whipping and bucking are not possible and there is no possibility of the arrow veering off track. I doubt that there is much friction even with wood tracks. Loading is almost as fast as with some closed muzzles but I prefer the type track that is relieved (widened) at the fore end of the gun barrel. This allows about six inches of shaft to be dropped into the track before pushing the whole arrow down the closed section of track. I don't understand the power claims of open versus closed muzzle. I am having trouble finding the physics which would support any difference.