Posts by vadimrok

Quote from Marco

There you go....

http://aquatech1.narod.ru/eng12.html

Thanks, man! Just found an original in Russian since the translation sucks big time. Over there most hunting is done in the fresh water with low visibility or in the saltwater for smaller fish, so rubber guns are not in use. Here it is a weapon of choice, over there it is not that popular. Plus rubber is a b*tch to travel with. So they reviewed non-rubber ones except one.
But it is a common knowledge that the handle has to be positioned in the back in such a way to minimize the recoil effect. That what they attempted to do it in Omer Airbalette I believe.

Overall some explanations are disputable, I believe, especially about reducing the weight of spear. It is wrong. But I will not get into physics of it here. I am impressed with the variety of whats available. I might even order something that can be serviced by me in the US.

Quote from Marco

Interesting post...

I've seen some hydropneumatic guns in action. Are you familiar with the Aquatech? Those are from Ukraine.

Well, I am also a Ukrainian product myself, but from some 21 years ago! When I left the country all guns available for purchase were pure garbage, so serious hunters were building their own. I am out of touch with a present gun development in the former USSR, so unfortunately I am not familiar with a present crop of their guns. But I can tell you that my father designed a dry-barrel air gun probably around 1980 and it turned out that a lot of people had designed a similar one without sharing any knowledge (it was no Internet back then!). A lot of innovation came from that era. For example, some people used shafts that were square in cross section and ROTATED slightly along its axis. It would create a spinning effect similar to the way bullet spins when shut out of the gun with internal spiral in the barrel. The shot was more accurate but those shafts were extremely difficult to make. And to temper was also difficult because of the type of the steel used. It had to be quenched in oil under a tremendous weight attached to a shaft if I recall... My father also designed a spring gun, were a metal spring would be used the same way a compressed air is used in the air gun. Only that gun was extremely simple and more reliable than a rubber one (the spring would last forever) and no seals were required unlike in the air gun. The problem was to find an appropriate steel which would make the gun the most efficient. The best one was used in the Kalashnikov gun, but it was a classified material and my father was not able to obtain one, so he had to settle for an inferior steel which made the gun very weak. I used it as child from the age of 7 on smaller fish.

Some crazies used molybdenum shafts, that is much heavier than steel so had a greater penetrating power. I'd better stop now.

Cheers!

Quote from Dan

It's an interesting proposition but those guns shoot so slow in the first place, that using a thicker shaft I think would defeat the purpose. I'd think recoil and accuracy would become an issue too. Have you actually shot an 8mm shaft from a Cyrano?

Properly heat treating shafts seems to be the last obstacle for every shaft maker I talked to. I figure then that it's not an easy thing to set up and/or get right. If you get stuck for the style shaft you need any 8mm shaft that is not too hard to drill will do, even a Riffe shaft. You shape the back with a grinder, put a point on the front, and drill two holes for the flopper pin and mono.

I just said i use them on stripers in the USA over the sandy bottom. In Europe over the rocks I shoot 7mm from an online shop which is tempered but has an integrated point. My 8mm are threaded so I change tips under water when they become dull. Slow? I do not see the shaft when I shoot my Cyrano 850.

As far as tempering, I know exactly what to do. I just do not want to build an oven, but I know EXACTLY how to build one. I also talked to Ray Odor from Florida and he confirmed that 15-5 and 17-4 SS has to be taken to spring condition called H900, which is an hour at 900 Fahrenheit, then aircool. See here for example: http://www.andersonshumaker.co…el/15-5-ph-stainless.html

Like I mentioned, my father for many years was involved with a lot of gun makers who designed and built extremely sophisticated and efficient guns. Some of them are still around, so I can always get an advice. Most these people worked in scientific laboratories and institutes back in the USSR so they definitely know what they are talking about

In all probability I will be building an oven good for tempering one shaft at a time at least 40" long made out of 15-5 and 17-4. It will cost about $200 do build. Should I do it, Iwill post the description. Most here use long shaft in their rubber gun, but if you temper the first 40", it will be perfectly fine

Quote from Tin Man

Yes, volume is a cubic function. But an inch of length is an inch of length regardless of the diameter. The RATIO between the volume (and therefore weight) of two shafts (of the same length) is proportional to diameter squared, not diameter cubed.

You are absolutely right! Pi*R1*R1*L/Pi*R2*R2*L = R1^2/R2^2 = (R1/R2)^2 = (8/7) ^2 = 1.306 in our case.

Thank you very much for pointing that out!

Quote from Tin Man

How? I thought area was PI x radius squared?

We are talking about the VOLUME here. Take a cube with a side of 1 inch. It volume would be 1 cubic inch. Take a cube with a 2 inch side. Its volume is 8 cubic inches. Weight is density multiplied by volume

Quote from Ryddragyn

Email this guy, he can either do it for you or give you the info:

vectormarineproducts@gmail.com

Thank you very much, will check it out!

Quote from Dan

Vadim, are you saying that a Cyrano will accept a 5/16 (8mm) shaft? To my knowledge the inner barrel of the Cyrano is smaller than the other air guns and will not accept a shaft bigger than 7mm in diameter. In any case the Cyrano is not designed to shoot a 5/16 shaft.

A 7mm shaft is too light to my taste, so I changed it to 8mm. I do not have a 9mm rear-end 'butt', I have a different way of attaching a line to the shaft. So my shaft just ends with a profile machined to resemble a threaded 8mm standard Cyrano end piece.

As far as Cyrano 'is not designed to shoot a 5/16" shaft" ... My father is a gun designer who designed and implemented several spring, air and so-called "hydro-pneumatic" guns (which is a an absolute thing of beauty, too expensive for commercial distribution, but perfect as a hobby. You INSERT a shaft in the barrel and pump water between shaft's end and a piston in the air chamber. The more strokes you make, the more power you get. By far the most efficient gun and small, the handle is in the middle...). On top of that he has a post-PhD degree in physics, so I f I need an advice about a technological viability, I have somebody to ask. He recommended me 5/16 shafts an I use them extensively.

And yes, my shafts go through the 30 pound stripers like a knife through butter... Because:

1) Weight. Because given the same length an 8 mm shaft is 1.3 times heavier than a 7 mm one (weight is proportional to the diameter ratio in the power of 2)

2) Efficiency. Cyrano has an inner diameter of the barrel at 11mm (better than lesser Italian guns at 13mm). When using a standard 7mm shaft, you have a cylinder of water that surrounds a shaft with the wall (11-7)/2 = 2mm. During the shot this water has to be expelled and pushed through the holes in the muzzle - a terrible waste of energy. As you know a Mamba kit is used to eliminate this issue to keep barrel dry inside. But when you use an 8mm shaft, the wall becomes 1.5mm - better! Ideally the shaft has to be 11mm in diameter, but the slightest bend will damage the inner surface of the barrel. So 8mm is OK provided your shaft is straight. Therefore I need to temper it. Because tempered shaft is either straight or broken this!

Cheers![/QUOTE]

Cheers!

Hello!

I use airguns exclusively (Cyrano) . Stock shaft is a rusting crap and a slide ring is an insult to sanity. So it is either to buy pre-made from Ray Odor or Scubastore or to make my own. Unfortunately pre-made ones for Cyrano (while tempered) are only 7mm (9/32") and without a front thread for a changeable tip. I use homemade 8mm (5/16") shafts made of 17-4 (630) stainless steel. I make everything myself (have an access to a mini-lathe) but tempering is a problem. I know all required info about a temperature regiment for a so-called H900 spring condition that most shops use, but I do not have an access to an oven. So my question is, has anybody tempered their own shafts, made an oven or knows somebody who offers this service. Also is H900 the best temper for hitting rocks, etc.

Thanks in advance

Greetings!

I am from NJ, originally from the USSR (presently Ukraine). Have been spearfishing from the age of 7 with a SPRING gun. Now spearfishing very sporadically with air guns and hoping to learn a few things from everybody here!