Pneumatic Guns - Power Reducer or No?

[steiney]

I'm new to spearfishing. I have my first trip planned with a friend who is a fairly serious fisherman (from a boat) but also new to spearfishing. I have just concluded many hours of reading and research. I have decided to go with a 55cm Cressi Saetta. The only thing I cannot really find any information on is power reducers on pneumatic guns.

There's a $30 price difference between the model equipped with the power reducer and the model without it. I'm interested to hear from others who use a pneumatic gun how important the power reducer is.

I will be hunting in reef and open shallow to shallow-ish water, with limited visibility sometimes. I can imagine that I could bend or break a spear tip or shaft if I fired at full pressure at a reef. I also want to minimize the damage or impact I cause to coral reefs.

So, does not having the power reducer on the gun limit the usefulness and broadness of application?

 

[Stamatis]

Well, I am new to pneumatics, I got mine a few months back, and it does have a power regulator. I guess I just had to have the option to reduce power. I have never used it because it's a 100cm gun used for ambush. The shaft is 7mm and I did hit rock once from 1,5m but it can take a beating... Now, a 55 gun is pretty short, and is meant to be used only in cavities and really low visibility conditions, with a trident usually... if that is the case, I don't think it's really important to have a power regulator. You just pump it to the pressure where it suits you. Anyway, it all comes down to your hunting style!

 

[Diving Gecko]

Since we talked about this on another thread, and since new users or potential buyers, may find this thread in a search I thought it alright if I C+P my answer and add a bit here, too:

I would say it depends on your hunting grounds and technique. If you are shooting a big gun in blue water, then no need for a PR (Power Regulator) and I would personally pull it out. But the last few weeks I have shot a Predathor 100 on the reef and even with the PR bulkhead doing a bit of throttling it's still powerful enough for the fish I can run into here. But having the PR is such a nice feature and the kind that you may not think you need before you have it.

E.g. two days ago, I shot seven fish on the reef, four of them was on full power as they didn't come super close but one of them came right up to me and even though there was water behind the fish, I shot it on low power to have the easy reloading when I surfaced. I also shot two red Googleeye fish in some deep caves. These fish are fairly small but very tasty so I sometimes take them if nothing bigger is around. But they like to stand right next to the wall but with the low power feature I had no problem shooting them up close and still not risk bending the shaft or getting it stuck. With a rubber gun, unless I had air left to unhook one rubber, I wouldn't have shot those two fish.

Stamatis' post above shows that the type of hunting probably more to say than the size of gun on this matter though. He also shoots a 100 but mostly with clear water behind the fish or at the longer end of the range. Here, in the Philippines where I am right now, on the same dive, I can do aspetto and may have a big jackfish or small tuna come in or a snapper lurking in and out of the range for a long shot - but if that doesn't happen, as I turn and ascend along the wall, I may see a small, tasty fish inside a cave. So, while Stamatis doesn't need the PR on his 100 gun, it's a huge bonus for me on the same size gun.
I do agree that on shorter pneumatics, a power regulator doesn't make that much sense - and it also starts taking up a lot of relative space in the gun making the high power shot less efficient, plus it makes the gun slightly more heavy which can be a nuisance as shorter airguns tend to be a bit heavy in the first place.

So, my personal take on it is that for a reef gun, I would say go with the power regulator - and remember, you can always pull it out later if you realize you never use it. You can't put it in if it wasn't there in the first place (the handles are different).

 

[popgun pete]

You can find out more here, https://forums.deeperblue.com/threads/pneumatic-speargun-compression-ratio.86054/, especially post #20.

 

[Andrew the fish]

I had 55cm pneumatic gun with reducer. Seemed like a good option to have at the time. Wasn’t Cressi, it was Mares. The power reducer is in fact a simple valve connecting big chamber or cutting it off. In the water that valve started leaking air and I had to move switch in its place so it would stop making bubbles. And then I left the switch at max position and tried never disturb it so it wouldn’t squirt another bubble. I also had a couple Cressi SL Stars, 55cm, with no reducer and that turned out being better choice. 55cm pneumatic gun is not overly powerful at its maximum pressure. PR switch seems like unnecessary complication.

 

[popgun pete]

The easy loading feature is part of the power regulator thanks to the non-return valve in the partitioning bulkhead. That means each loading attempt is not entirely lost if you cannot make the piston latch on the first attempt. This becomes more of an advantage on long guns where you may be having difficulties if surface conditions are rough. Usually the shortest 42 cm guns don’t have a power regulator and it is optional on guns up to 70 cm, from there up the power regulator used to be standard. Companies such as Salvimar made having it a different model, but regulator equipped guns are a lot more versatile around reef areas as in a sense it gives you two guns in one.

 

[Diving Gecko]

I had 55cm pneumatic gun with reducer. Seemed like a good option to have at the time. Wasn’t Cressi, it was Mares. The power reducer is in fact a simple valve connecting big chamber or cutting it off. In the water that valve started leaking air and I had to move switch in its place so it would stop making bubbles. And then I left the switch at max position and tried never disturb it so it wouldn’t squirt another bubble. I also had a couple Cressi SL Stars, 55cm, with no reducer and that turned out being better choice. 55cm pneumatic gun is not overly powerful at its maximum pressure. PR switch seems like unnecessary complication.

I personally don’t agree that’s it’s overly complicated but yes, on a smaller gun it may not be worth it. Nor on the longest ones if you are looking for maximum performance especially for heavier shafts.
But I think they are a great feature - if you ever shoot near rocks or into holes - for guns around 70-115ish.

The traditional italian design like the Cressi uses two o-Rings. One on the bushing valve and one on the rod exiting the handle - which ends in the knob. If the latter starts leaking, you’ll loose air in the gun. If the first one leaks, you don’t loose air - just the function of the lower shot. Though the bushing even with a leaking o-ring would probably still throttle the shot on low power. But you’d loose the ability to take the last shot of the day on low power and enjoy an easy reloading when back in the water.

Either way, both are fairly easy fixes of one knows how to service an airgun - which most users will learn sooner or later.

Finally, there’s an easy non-destructive way to get rid of the feature but still be able to put it back in. Pull the PR bulkhead (also called the ‘block’) out of the gun but leave the rod in the handle as that will serve to seal the gun. I think you can even take the elbow off which the knob sits on. Then you don’t even have that protruding. And as said, you can easily revert to the stock setup if you do wish.


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[popgun pete]

Replacing a leaking "O" ring on the power control rod is the one job that requires dismantling most of the gun. You can read about how to do it here.
https://forums.deeperblue.com/threads/pneumatic-dismantling-how-to-get-inside.90024/#post-837717 post #8 and onwards.
Make sure you remove the trigger and pull the trigger transmission pin out first after you depressurise the gun or you risk bending the pin.

 

[popgun pete]

The exploded parts diagram can be found here. https://www.cressi.com/easyUp/file/instructions/SP_Saetta.pdf

 

[popgun pete]

As the power regulator block is clamped in position between the inlet valve body, which is effectively a nut screwed on the rear of the inner barrel, and the circlip that anchors in the barrel groove just forwards of the grip handle that locates hard up against the front of the partitioning bulkhead, you have to undo the inlet valve body to remove the circlip. Note that in the Saetta this circlip also forms the support base for the non-return valve which consist of a biasing spring, inox ball and an “O" ring.

 

[Diving Gecko]

I found one more nice thing about the power regulator on the 100 gun I’ve been using recently.
The place I’m visiting and spearing at now is near mangroves and rivers and as a result the visibility can be quite bad. That’s not necessarily a bad thing only as fish also tend to come closer to you before they spook. Actually, they can come so close that I can’t track the gun fast enough and even a 100 airgun becomes too long but that’s another story.
What I did find is that a lot of the time once the low tide moves the mangrove water into the hunting spots and reduces the viz, I start taking most of my shots on low power. For two reasons, mainly because there’s still enough power and because I don’t want to bang the shaft into a rock on the edge of the visibility.
Shooting a fish on low power and having the super easy reloading just adds to the bliss of having caught a fish[emoji4].

Long story short: bad viz is another scenario where the power regulator comes in handy.


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[Andrew the fish]

I agree. But, we were talking about 55cm Cressi, which in my opinion does no need reducer as it is already half gun compared to your 100. I never said power reducer is “overly complicated”. I said “unnecessary complication” on a 55cm gun, which Stanley, still new and probably long time inactive member, was considering buying 3 years ago.

 

[Diving Gecko]

Threads like these serve as an archive for new users too so I don’t mind putting my thoughts here if the subject is interesting. I think I also agreed that on shorter guns I wouldn’t be in favor of a PR. And while the OP does talk about a 55 the title of the thread talks about regulators in general.



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[popgun pete]

There is one advantage of the power reducer on even a short gun and that is if the gun has to be discharged in a controlled manner. You can do this by placing your spear tip against a solid object such as a timber board, like a stair step. With the power regulator set to low you can then pull the trigger while leaning on the gun and control the rise of the gun off the spear. It can be done at full power, but you need to be leaning hard down onto the gun to stop it getting away from you. Once I encountered a diver trudging up the beach with his loaded pneumatic in his hand, it was a Cressi SL and I told him this was very dangerous. He said the safety was on, but I replied as a trigger blocker it meant nothing. I suggested that he immediately uncock the gun before he shot someone and trashed the reputation of the sport and being near the timber staircase that descended the short cliff onto the beach he used that in the manner described.

You can also do it with the hand loader on the spear tip on a short gun while you brace for the initial jerk, but you need to know what you are doing. Don’t try this on a single power gun!

 

[popgun pete]

I should add that on a very short gun, such as the Seac-Sub Asso 30 cm, the volume of the tank compared to the regulator block is not much larger, hence the reduction of the regulator is not that great. That is why very short guns don't have one, unless you are Hang Fung Industrial who put one on their shortest model as they did not have a single power handle. I have never known anyone who purchased one!

I just checked to see if this tiny gun was still being made, it is, but now they have added a knife to the butt. Plus they now offer non-regulator models.

 

[Andrew the fish]

^^^ push dagger, prohibited device in Canada.