Inalex Alpha C1 Pneumatic Speargun

Diving Gecko said:

Sadly enough I got insulted for asking the same question on another forum so thanks so much for helping me out. I guess I was naive in thinking that Pete and Aleks couldn't make honest mistakes like these. I just looked at the numbers and didn't understand if there was any secret sauce or Mirage'ish tricks in the gun.

Click to expand...

Hmm, "honest mistakes like these", are you kidding? Embarrassed you may be, but insulted, no.

Alex with some of his guns on a good day. Note the length of the "Alpha C1" spearguns.

Note the size of the trident for the gun on the right in this photo. I think there is a photo somewhere of a bunch of fish all skewered with a single shot, which is pretty good for any gun as it takes a lot of gun power to propel a trident at high velocity and have the necessary energy to rip through a number of victims.

found the photo!

Here is another fish that has been skewered with a trident head fitted to an "Alpha C1" speargun.

Here is a video of the "Alpha C1" shooting over a long distance underwater. While it can slam its shaft right through the target a contemporary band gun can barely make the distance to the target. Gun power on display here as the "Alpha C1" is virtually a straight line shooter over this distance.

video number vk.com/video224496305_171564282 if link does not work, which for some reason here it does not, but it does work elsewhere!!

I have decided to buy an "Alpha C1" in order to try it out. The gun was ordered recently and apparently you can shift the handle position if (a) you have an alternate length trigger pull rod and (b) you know what you are doing. Initially I will have the grip handle set right back as that provides improved accuracy over say a mid-handle gun.

Hopefully I can load it, just to make sure I ordered the 97 cm model so that it is within my reach. My GSD "Katiuscia" is a much shorter gun, so easier to squeeze down on the 14 mm diameter inner barrel used in that gun. At 30 bar they take some pushing, you don't get anything for nothing!

The "Alpha C1" arrived today as while collecting another item at my post office I was surprised to see the postal worker come out from the parcel storeroom at the rear of the shop also bearing a long package. It was unopened, so had been passed without any concerns by our Customs, which is good as many years ago spearguns could "disappear" for long periods while officialdom puzzled over what they were and never bothered to ask anyone.

I unpacked the "Alpha C1" gun today as the weather had improved, it was packed inside a long corrugated cardboard roll covering a length of spiral wound aluminium foil duct type tubing which was squashed up around the gun and two spears. Very innovative as with everything imprisoned in the flattened alloy tubing nothing could move or rub, or poke out. Inside that again were layers of bubble wrap held with unbelievably sticky thin masking tape. It took me about an hour to unwrap it all as I did not want to chop anything accidentally with my Tullen shear cutters which will nearly slice through anything.

Here are some photos which I took before putting the gun together, the grip handle is a two-piece "skeleton" style alloy casting that clamps onto the outer tank, the blue rubber grip handle pushes over the lower grip section once you tighten up the 3 cap screws that hold the grip together. The trigger hook has forward facing claws on its top that engage the gun's pull rod, you pull the trigger and the pull rod in turn moves an internal slide that allows the locking ball to drop down which releases the firing valve and the gun shoots.

You can see the pull rod here; the trigger's tiny upper claws grab onto that spade like horizontal tab on the front end of the pull rod. Above the position where the pull rod enters the gun body is the automatic line release lever; you pull the trigger, the internal releasing valve slams rearwards and operates the line release lever before the shaft rockets out of the gun hauling the shooting line behind it. The releasing valve, which can be set to different degrees of rearward movement by rotating the rear butt, opens the inner barrel up to full gun pressure and sends the piston forwards which in turn propels the spear.

Here are some photos of the grip handle being fitted; for a comparison the Scubapro "Magnum" (the ancestor of the "Vintair") is shown alongside, it being my regular user "popgun". You can just see the pull rod poking out of the rear of the grip handle on the "Alpha C1". The slightly conical rear butt on the gun pushes forwards to reset the releasing valve after each shot and revolves on a left handed thread to adjust the firing power before the shot. By screwing it fully forwards the gun cannot shoot as the releasing valve will be blocked from moving even if you pull the trigger. After loading one of these I would be inclined to use full power as the power regulator is a throttle, but as always the regulator can save your spear tips if you have your intended victim backed up against some rocks or looking out of a cave.

and here they are side by side.

I have suggested to Alex that he consider using an adjustable handle on the “Alpha C1” which would make it something like the old Technisub “Drago”, but with the much better releasing valve system already used in his “Alpha C1” gun rather than the forward latching mechanism used in the “Drago” which was a poor choice for a trigger mechanism as the three ball sear in the muzzle was exposed to seawater. Their pull rods work in opposing directions, so the “Alpha C1” moving position trigger design would need to be engineered somewhat differently to that of the “Drago”.

It is a great gun, very powerful and a rarity in these days where nearly every other pneumatic speargun is a distant relative of the Mares "Sten". Exceptions are the "Airbalete” family which includes the Sporasub ONE AIR, however they all use a sear tooth that holds the mushroom tail on the piston and shoot when the tooth is moved down by pulling the trigger.

The only drawback of the "Alpha C1" is that it is not a great floater as there is quite a bit of weight in the cast alloy handle frame (250 gram) and the rear end of the gun floods in the vicinity of the releasing valve and automatic line release. However if you remove the handle then the gun floats at a slight angle with the muzzle poking out and the butt submerged just beneath the surface. Therefore a lighter handle frame would transform it. I was just looking at the gun the other day and thought that it would be easy to move the handle along the gun, but it would require a longer pull rod that the trigger could clamp to at any position. Right now you get a pull rod of a length fixed for your gun’s current handle position, but it is not a big job to change it. The Technisub patent has probably lapsed by now as its priority date was 31 January 1970 in Italy.

Cost of the gun is high because they are made to order, they are not mass produced and are a lot more expensive than factory guns, usually costing an extra 75% or more above the cost of the factory guns. If you want something different and more sophisticated in its workings then you have to pay for it.

There used to be a web page, however it seems to have disappeared; inalex.biz from memory..

I received some spare parts with my “ALPHA C1” gun, but there is nothing that a competent workshop could not make provided they had something to copy

Here are the Operating Instructions for the Inalex "ALPHA C1" pneumatic releasing valve speargun.

Inalex ALPHA-C1 Speargun Operating Instructions A

NB. Read and understand all the instructions before attempting to use the ALPHA-C1 speargun! The ALPHA-C1 pneumatic speargun uses a unique operating system which is very different from that used in other spearguns of this type.

Instructions on how to pump up or pressurize the ALPHA-C1 gun

1. Turn the power regulator cylinder anti-clockwise (which is the rear rubber covered butt assembly) on its left handed screw thread until it stops moving, this places the ALPHA-C1 gun in "safe mode". The next step is to switch the muzzle to "air transfer" mode, but before this can be done the piston has to be pushed to the rear end of the inner barrel.

2. Insert the spear into the muzzle, place the hand loader on the speartip and push the spear fully into the gun until it stops moving. This action jams the spear tail into the piston face and pushes any air in the inner barrel back into the receiver (which is the outer tank).

3. With the piston now withdrawn from the rear internal face of the muzzle, unscrew the muzzle by hand so that the air transfer ports in the inner barrel are exposed. When the air transfer ports are open air can either enter or leave the ALPHA-C1 gun through these ports.

4. Pull the spear forwards in the gun, this drags the piston forwards and creates a suction in the inner barrel which will draw air from the surroundings when the piston seals move past the now open air transfer ports.

5. Now repeat the previous spear loading action which will push the air that has just been drawn into the inner barrel through an internal check valve and into the receiver. This pumping action can be performed for the required number of inner barrel pump strokes that will produce the desired level of internal air pressure and hence loading effort when using the gun.

6. Twist the muzzle in the opposite direction to fully close off the air transfer ports, then pull the spear free from the muzzle with a strong jerk.

7. Turn the power regulator cylinder to open it by only 1/3 of a turn as this will limit the operating stroke of the gun's releasing valve.

8. Pull the trigger, the above setting of the power regulator cylinder is important as it will only allow a small flow of air inside the gun to occur initially.

9. Gradually unscrew the power regulator cylinder to move it rearwards which will progressively increase the flow of air from the receiver (outer tank) into the inner barrel which will increase pressure on the piston and hence muzzle in a controlled manner. The ALPHA-C1 gun is now ready for use.

Preparation for first shot from ALPHA-C1 gun

1. Before attempting to muzzle load the ALPHA-C1 gun the releasing valve must be reset. To achieve this the power regulator cylinder can be either pushed inwards by placing the butt against your body (the rubber covered butt is sprung loaded) or you can screw the power regulator inwards to the "safe mode" position which will achieve the same result. The latter is the safest option as the gun cannot shoot in "safe mode" and is therefore recommended.

2. Insert the spear into the muzzle and fix its tail into the piston which will be at the front end of the inner barrel.

3. Place the hand loader on the speartip.

4. Push the spear into the inner barrel, this action will force the compressed air from the inner barrel into the receiver via a check valve that prevents this air returning to the inner barrel. This can be done with a number of spear insertions if the end of inner barrel travel is not reached the first time as any remaining air in the inner barrel will progressively drop in pressure as it returns the piston to the muzzle each time you cannot accomplish the full stroke. Once the piston has been fully pressed to the rear end of the inner barrel virtually all the compressed air has been transferred to the receiver from the inner barrel and a vacuum forming behind the piston will stop the piston from moving forwards again.

5. If the gun is not already on "safe mode" then set the power regulator cylinder to this position (cylinder fully forwards).

6. Install the shooting line on the gun's line wrap system and complete any other line rigging preparations.

7. Unscrew the power regular cylinder outwards which will remove the gun from "safe mode". Maximum power for the shot will be achieved with the power regulator cylinder moved fully back. To reduce power it is moved forwards by screwing the power regulator cylinder anti-clockwise (i.e. inwards) as this progressively reduces the opening stroke of the releasing valve which is operated by pulling the trigger. Remember that the power regulator cylinder uses a left hand thread.

8. Hold the gun firmly, point it in a controlled fashion, pull the trigger, the gun will shoot. Fire the gun only when fully submerged, all other use is forbidden.

9. After the shot the piston should be at the muzzle, its presence can be detected by looking at the muzzle relief ports.

10. The releasing valve will have moved rearwards after the shot, you will be able to see it by looking through the view holes in the rear of the gun as its rear end is a piston that interacts with the inner column of the power regulator cylinder. For the next shot this piston must be moved forwards to relock it by either pushing on the rear butt or screwing the power regulator column inwards which will reset the releasing valve, you can then reload the gun for the next shot. You should check the success of the relock by looking through the view ports if you push on the rear butt, however screwing it in ensures that the relock occurs.

Depressurizing the ALPHA-C1 gun

1. Turn the power regulator cylinder anti-clockwise (which is the rear rubber covered butt assembly) on its left handed screw thread until it stops moving, this places the ALPHA-C1 gun in "safe mode". The next step is to switch the muzzle to "air transfer" mode, but before this can be done the piston has to be pushed to the rear end of the inner barrel.

2. Insert the spear into the muzzle, place the hand loader on the speartip and push the spear fully into the gun until it stops moving. This action jams the spear tail into the piston face and pushes any air in the inner barrel back into the receiver (which is the outer tank).

3. With the piston now withdrawn from the rear internal face of the muzzle, unscrew the muzzle by hand so that the air transfer ports in the inner barrel are exposed. When the air transfer ports are open air can either enter or leave the ALPHA-C1 gun through these ports.

4. Pull the spear forwards in the gun, this drags the piston forwards and creates a suction in the inner barrel which will draw air from the surroundings when the piston seals move past the now open air transfer ports. Note that up until this step the procedure described here is exactly the same as that for pumping the gun.

5. Next pull the spear free from the piston with a strong jerk leaving the piston at the muzzle end of the inner barrel and the inner barrel at ambient pressure (since the air transfer ports are open). The majority of the compressed air in the gun is still held in the receiver (outer tank), but locked up by the releasing valve which is closed as the power regulator cylinder is in "safe mode".

6. Turn the power regulator cylinder to open it by only 1/3 of a turn clockwise as this will limit the operating stroke of the gun's releasing valve.

7. Place the gun with the muzzle pointed downwards and pull the trigger which allows the internal releasing valve to open and release the remaining compressed air in a controlled manner rather than in one large violent burst of air as the opening of the releasing valve is limited in its movement by the prior setting of the power regulator cylinder to a low power position.

8. To increase the rate of air flow from the gun rotate the power regulator cylinder gradually in the high power direction (clockwise). This controlled release of compressed air prevents the excessive loss of lubricating oil from the gun, although a small amount of oil will be lost in the form of fine droplets.

The ALPHA-C1 gun is now fully depressurized.

Checking the trigger operation of the ALPHA-C1 gun

1. Press firmly inwards on the rear butt, or screw the power regulator cylinder inwards to “safe mode” which will ensure that the releasing valve is reset and is locked in place by the gun’s internal trigger mechanism. Do not push the spear into the barrel or move the piston back, the piston should remain in the muzzle for this independent check of the trigger function, hence there will be no possibility of a shot.

2. When the releasing valve is properly locked the rear line release arm will be immobilized in the narrow longitudinal slot which is positioned just in front of the power regulator cylinder.

3. Unscrew the power regulator cylinder to remove it from "safe mode" and then pull the trigger, the releasing valve will be pushed back, there will be a clicking sound and the line release arm will be free to pivot forwards. The mechanical interaction between the releasing valve and the line release arm allows the synchronization of the gun shooting the spear and the release of the line loops or wraps installed on the gun.

4. Note that the releasing valve’s rearward movement is powered by the elevated air pressure inside the gun, if the gun contains no pressure then the releasing valve will not move back.

5. Check the bolts on the grip handle for tightness and the clearance of the pull rod in the various slots in the gun as the pull rod needs to be able to move freely when you pull the trigger. The grip handle needs to be firmly fixed on the receiver for the pull rod to be effective in operating the internal trigger mechanism, so do not loosen the bolts. The gun must not be used if the grip handle is not tightly clamped to the receiver as the receiver must be prevented from moving with respect to the handle during the shot.

Safety and Maintenance

Note that the use of a left hand thread on the power regulator cylinder provides a level of security which prevents the ALPHA-C1 gun from being used by unauthorized persons who will be unfamiliar with the gun's operation.