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Which one? Roller, double bands or triple bands?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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popgun pete

Well-Known Member
Jul 30, 2008
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The main reason for adopting reverse triggers is that they are shallow and can allow the grip handle to sit higher up so that the spear axis is not far above your hand. The downside is that they only dry fire thanks to the weight of the sear lever arm as they usually have no biasing spring on that arm. Exceptions are the Sea Hornet and Biller which use a leaf spring to bias both levers, but that deepens the mechanism housing. If you want more band draw then you need a longer gun. It would be possible to bury a standard trigger in the speargun grip and fire it via a remote trigger from in front of the grip, much like a mid-handle gun using a short link or pushrod.

The sear lever pivot pin position with respect to the sear lever tooth determines how readily the sear lever rolls. On standard mechanisms it usually sits below and just behind the tooth, but on reverse mechanisms it can be found further back. This may tend to cause drag on the tooth as it tips through a smaller arc, unlike standard mechanisms where the sear lever tips through a much larger arc to let the shaft go.
 
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DiveHacker

Active Member
Jun 17, 2020
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@DiveHacker great questions. Why don't you insert a link to the youtube video, the forum software will take care of displaying it ;)

My 2 cents: Your opinion counts! You've clearly though about this and started researching it.

Re. reverse triggers
I bought 2 spearguns last year, both have reverse triggers. My other 2 spearguns are wonderful for my needs, Omer XXVs, which will continue to be my "main squeezes". I bought them shortly before the Omer Cayman* came out, which some claim was the first reverse trigger speargun (if not ever then perhaps the one which started the trend). My XXVs are great, would they be better with a updated reverse trigger T10 mech - quite possibly but (1) sadly they are no longer available and (2) they are all about agility and fast tracking more power might be useful but perhaps it would spoil them (they are very light)?

*As I remember it, when the Cayman came out, Omer didn't make much of the extra band-stretch power of the reverse -trigger. I seem to recall the adjustable, constant tension trigger being the main feature. Or did I just miss the headline?!

I believe most SA-style railguns (e.g. Rob Allen, Rabitech, Mako, Orcas, Pelaj, Hammerhead) do not yet offer reverse trigger mechs as standard nor as an option (but there are some aftermarket cassettes for the Rob Allen that do provide a reverse trigger). I once asked RA about this and this comment at the time was that people found them too hard to load; I don't recall if Rob Allen offered a loading butt option at the time, they do now. Supposedly a lot of railgun users have no desire for a loading butt, I would definitely get one, given the option! Reverse triggers have really taken off recently - who doesn't want 5cm of extra band stretch power?! - not sure what other downsides reverse triggers might be but I know somebody who might @popgun pete and @foxfish
I'd be surprised if Rob Allen aren't already working on a reverse trigger but, as I said, 3rd parties already have so perhaps they figure that address the need until the latest fad blows over?

Re. getting more power from shorter guns, yes it would. My 95cm roller has a reverse trigger too - so much band stretch, so much power! :D

Here is one where he shows how larger diameter bands a essentially less effective when it comes to penetration anyway. You have to watch the video, but he concludes a 7mm shaft is best with 14mm bands. Omce shafts get larger the 14mm bands don't do as well and going up to 14.5mm does in fact work much better. So there is a mix there of common knowledge being both correct and incorrect.

Here is the one I was referencing. Maybe better to watch this one before the above, because he is showing why he prefers these 14mm bands in this one. This is where he out performs a 3 band riffe at the end which is just incredible. I am not even sure what to think about that.
 
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xristos

Well-Known Member
Sep 5, 2013
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Here is one where he shows how larger diameter bands a essentially less effective when it comes to penetration anyway. You have to watch the video, but he concludes a 7mm shaft is best with 14mm bands. Omce shafts get larger the 14mm bands don't do as well and going up to 14.5mm does in fact work much better. So there is a mix there of common knowledge being both correct and incorrect.

Here is the one I was referencing. Maybe better to watch this one before the above, because he is showing why he prefers these 14mm bands in this one. This is where he out performs a 3 band riffe at the end which is just incredible. I am not even sure what to think about that.
There is one very crucial parameter that this guy doesn't test and it is shaft velocity. It could be that the pathos shot is precise but too slow to kill fish. But with same shaft weight between the two guns i dont think this is the answer.
 
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DiveHacker

Active Member
Jun 17, 2020
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I believe he is trying to infer shaft velocity, or momentum, using his penetration tests. He test the effects rubber diameter has on the same shaft, and finds smaller shafts penetrate better with smaller bands, which I believe you could infer it thus had a higher velocity with the smaller band. He finds larger shafts (8mm and up) simply can't be propelled as well by those same 14mm bands that we so effective with the smaller shafts.

I don't pretend to understand it all, but when i get in the water I am going to try this. My new gun is being shipped with two 16mm bands and I will probably shoot and target practice with it a while and then swap to the 14mm. I probably wont be nice enough to make a video however haha. But in any event, his videos have encouraged me to experiment with thinner, easier to load bands that may in fact be more accurate and more penetrating.
 

Leander

Well-Known Member
Oct 17, 2017
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Has anyone ever tried making a shaft from a different material? There are plenty of alloys that are more dense than steel. If you could incease the shaft's weight while keeping it the same diameter you'd increase penetration at distance a lot.
 

Mr. X

Forum Mentor
Staff member
Forum Mentor
Jul 14, 2005
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Re. Spear material
My RA railgun had a spring steel shaft, possibly galvanized but not stainless. Great spear but can start to rust after a lot of use, so best to wipe with oil. Nice, big well tuned flopper.

My Omers and Apneas have stainless steel spears. The Omers are the opposite of the RA spears, very slim, small, very light flopper. The Apnea spears seem in between the two, even though slightly thicker than the RA. The Apneas also have the Rockwell hardness, HRC, etched on them :)
 
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