SpudFiles

How does something like this compete with something like a shotgun and bean bag?

No chemical propellants must be a plus in someones book.

You don't think a sling shot with a big rubber ball would do the trick? I'm not ragging on the gun, its a beautiful piece of work. What I am questioning is where it fits in a market like that.

Moonbogg wrote:How does something like this compete with something like a shotgun and bean bag?

Plenty when you think about it.

No chemical propellants must be a plus in someones book.

A hybrid cartridge was being contemplated in the initial stages if I recall correctly, but the advantage of a pneumatic is that you don't have storage and carriage problems of pressurised flammable gas, and it's mechanical in operation so no ignitor batteries or mix numbers to worry about.

Other advantages include:

training cost - a pneumatic cartridge can be refilled and reused with ease and at a much lower cost than buying a new solid fuel cartridge, so you can give your officers more range time for the same price.

cartridge shelf life - the only part that will really wear out is the seals, which can easily be replaced, unlike a solid fuel cartridge that has to be disposed of after a number of years

versatility - a 40mm bore lets you use a variety of payload projectiles (CS gas grenades for example) with high capacity, and the fact that the power for the cartridges is directly proportional to the pressure you take them to, you can easily have low-medium-full power range of cartridges available to the operator by simply filling to different pressures.

You don't think a sling shot with a big rubber ball would do the trick?

That would not give you the power or accuracy available to this launcher, and both criteria are essential for riot control situations where you need to reach out from a safe distance and precisely target priority individuals.

There's a distinct advantage to 40mm over 12 gauge in less lethal applications.
That ~5x increase in the area of the projectile means that it can hit harder without worrying about piercing the skin.

It's too large to easily pierce the eye (avoiding repeats of the Victoria Snelgrove case), it won't fit between ribs, and it can be given the necessary mass without resorting to high density materials. (And as we know, sectional density = penetration. And penetration is bad in less lethal.)

USGF wrote:Like Velocity mentioned though, if the clients so far have not objected, it must not be a major issue.

Just because something hasn't been noticed yet doesn't mean that it will never be. Some things may only rear their head in certain situations.

It took me quite a long time after buying my previous camera to realise why I should have bought one with a wide angle lens. It wasn't an issue most of the time, but there were those occasions when it was beyond frustrating not having one.
Such a major issue - even if it only crops up occasionally - that it's bloody unlikely that I'll ever consider buying a camera without one again.

Still, regardless of whether you take it as an important problem, it's still something you can consider and perhaps improve upon.

Ragnarok wrote: Some things may only rear their head in certain situations.

My point exactly. Try to minimize misfires due to leaking seals or abusive handling.

BTW what about that m16 grip with an inbuilt 3way valve that you planned to build ? are you working on it ?

POLAND_SPUD wrote:BTW what about that m16 grip with an inbuilt 3way valve that you planned to build ? are you working on it ?

Poland, sales of misc parts and guns has been pretty brisk. Mike has had a couple of machines pretty busy making parts. There is some development, but progress is slow. Stay tuned.

USGF

JNLWD flyer

Ragnarok wrote: Downloaded from youtube, ripped sound from the file, then studied it in Audacity. There are clear peaks for pilot, muzzle blast, and impact. All are quite clear sounds, but the report and impact can be identified doubly reliably by their timecode relative to the video.

Looks accurate, I appreciate you taking the time to support your statements.

Ragnarok wrote: The lock time is not always quite that long (in some cases, it's a little under half the ~150 ms of the slower cases), but I am confident that I'm measuring it correctly.

It is a poppet type pilot valve in the cartridge so if pushed slow (like suggested with firearms) it will vent the pilot off slower. A brisk pull will vent quicker. Testing with the fill apparatus (1/8" 3 way ball valve) to vent the pilot rapidly offers a near instant vent time but no noticeable velocity difference. Either venting slow or long the piston winds up in the back position so I think its safe to say there is complete dump regardless of vent speed. I suspect with some minor geometry changes to the poppet valve stem (coned) we could improve the pilot vent time if we felt it needed.

Ragnarok wrote:It's a statement of my opinion. If you found it offensive, then I apologise, but I'm not going to pussyfoot around sugar coating things when we're both mature adults.

... okay, I lie. I'm an immature adult. :tongue3:
Stupid jokes aside, criticisms are not always going to be completely sanitised.

By all means, please do not sugar coat. The statement "major problem" is just not supported well. Listen, the device cartridge is charged with gas, loaded with projectile, inserted in to firing device and when trigger is pulled, projectile goes down range at desired speed much like a typical firearm... No major issue I can see. There are some minor issues and this is a prototype for testing and ironing out the details.

Furthermore, there is so much design into this relatively simple device that the direction may not be apparent at first. Many of the cannons on SF do not need to take into account factors such as manufacturability, reliability, compactness, aesthetics, ergonomics, etc...

Ragnarok wrote:If it's taking at times 150+ ms to vent and fire, then, yes, in my opinion there is a problem somewhere - it shouldn't really need to take that long.
In some of the situations this may be employed in, that may well multiply in to a bigger problem.

Like how?

Ragnarok wrote: Were I working on this, I'd want to bring the lock time down. Whether you want to is entirely up to you.
(And I intend absolutely no subtext of my opinion being superior. It's not. But it's there if you want it.)

What are you working on?

Moonbogg wrote: You don't think a sling shot with a big rubber ball would do the trick? I'm not ragging on the gun, its a beautiful piece of work. What I am questioning is where it fits in a market like that.

Not sure where it fits in the market either. This was a funded project, we attained most of the goals thus far... there has been some interest, I'm not holding my breath. Although it has been a great business card for other opportunities hence my relative lack of SF banter.

Check out http://www.wired.com/dangerroom/2010/03 ... elmo-rifle They were awarded $830k from the army to develop.

Check out our flyer from the show. Rubber balls are OK, but drag and accuracy suffer. Our CR80 round has great stability and speed profile. One of the major issues with the shotgun bean bag rounds is that they are lethal up close and wildly inaccurate (some are not hitting target at distances of 25'!) With an efficient design the speed profile is more consistent and offer non lethality at the muzzle while maintaining energy over longer distances. On the flyer you can also see our Twist and Tune design. The foregrip area twists, to expose port openings offering 25% reduction in energy (with the CR80). Interesting concept, and all the rage with the non lethal folks but in my opinion but unnecessary with a well designed round.

Ragnarok wrote: There's a distinct advantage to 40mm over 12 gauge in less lethal applications.
That ~5x increase in the area of the projectile means that it can hit harder without worrying about piercing the skin.

It's too large to easily pierce the eye (avoiding repeats of the Victoria Snelgrove case), it won't fit between ribs, and it can be given the necessary mass without resorting to high density materials. (And as we know, sectional density = penetration. And penetration is bad in less lethal.)

I will agree here with Rag.. There is not a lot of information about human tissue tensile strength. The research we've done shows anywhere from 170 - 700 ft*lbs per square inch. Our CR80 is 2 square inches so we've adjusted speed and fill pressure to put out 340ft*lbs (170 per square inch) at the muzzle. Also, the crumble zones at the fore front increase the duration of energy transfer also lessening the lethality possibility but offers lots of knock down power.

jagerbond wrote:It is a poppet type pilot valve in the cartridge so if pushed slow (like suggested with firearms) it will vent the pilot off slower. A brisk pull will vent quicker.

So there's no hammer valve, just a direct lever to the pilot? Surely it would be very simple to have a double action trigger mechanism that would give a predictable release point and consistent pressure every time?

LVVWS

Very interesting, is it the multi-shot hydrogen fuelled combustion it appears to be? Also, that looks very much like the drum magazine used by the FN303:



Have you tried out any existing 40mm projectiles in the cartridge, and any plans for a stinger style rubber ball shotgun round?

jagerbond wrote:Like how?

Long or unpredictable lock times are obviously not good accuracy wise. And your end users are less likely to be repeat customers if they start to have doubts about its accuracy.
But I may be overestimating the problem. Have there been any tests with "hard to hit" targets (partially obscured, longer distances, movement - particularly movement)?

What are you working on?

Nothing - at least not in that sense.
What I meant is sort of an "If I were you, this is what I'd want to do", but phrased in a less snobby way.

jackssmirkingrevenge wrote:Very interesting, is it the multi-shot hydrogen fuelled combustion it appears to be?

"To begin with inventor Bruce Lund intended to use a mixture of hydrogen and oxygen to propel slugs from the LVVWS, having successfully used such a system in a toy rocket, but hydrogen was seen as a logistic burden by the military. The latest versions of the gas-gun now use MAPP fuel canisters of the type employed in nail guns among other applications."

Missed that, serves me right for skimming through articles when I'm supposed to be working

they say that the gun shares some features with propane/mapp powered tools... I am pretty sure that it has some sort of piston based mechanism to expel spent gases