SpudFiles

A little diversion from the day-to-day I put together, combining custom machined parts with over-the-counter brass fittings from Home Depot.



The working principle is similar to my pneumatic ballistic knife, a piston pushing on the projectile that is held in place with a ball detent. Moving the collar - either by pulling it back or by striking the whole thing against a target - displaces the balls and frees the projectile, allowing the air pressure to push it out.

Here it is in action against a defenseless biscuit tin and MDF sheets:

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More views, note that the fill valve is one of these as fitted to airsoft gas grenades and magazines. The penetrator is a length of 7.5mm dia HSS rod round to a point. Since my safety record is less than stellar, I've also added a grenade style safety pin





I've been using 850 psi of HPA from a paintball tank but it could also be used with one of these 12 gram fed devices.

Saw your post on reddit. Again, this is awesome. The actuation looks very smooth. This post answered the question I had over there - I was wondering whether the bolt was driven directly or by a piston. What's the threading on that fill valve? This could open up a lot of opportunities for me.

Certainly been a while since I've seen any stand-alone builds from JSR inc, although not a fascinating epoxy-slathered prototype like they used to be, it certainly looks neat, and looks like it works smoothly too, nice build

You know you ought to be careful, with your track record of smiley face destruction, you're lucky the UN haven't charged you with genocide, I'm guessing the death toll might well be into the thousands by now,

PVC Arsenal 17 wrote:I was wondering whether the bolt was driven directly or by a piston.

It's basically this concept made a bit more professionally.

What's the threading on that fill valve? This could open up a lot of opportunities for me.

M5x0.8 but 10-32 is practically identical.

I'm guessing the death toll might well be into the thousands by now

I'll give them something to smile about

That thing is downright scary!

Brian the brain wrote:That thing is downright scary!

Like it's creator then

Some progress, I made a lighter (8 gram) projectile with a brass head and aluminum tube, flies straight and penetrates better. Also tried "ballistic gel" for the first time, based on this method, what fun!

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That's actually a pretty neat little toy. Is the mechanism still easy to trigger at 850psi?
Also, despite my aversion to pneumatics of any kind, I feel an inexplicable urge to build one
Given my current supply situation though, I would have a choice of pressurizing it with either hydrogen or oxygen, neither of which seem like the safest of ideas for handheld operation.

Nice one JSR, Now I'm think of making one for myself
Got a bunch of 3mm steel ball bearings, do you think they can be used to lock the dart?

This could open up a lot of opportunities for me.

I'm selling these which I got from all these gas mags I converted.

Also, despite my aversion to pneumatics of any kind, I feel an inexplicable urge to build one

Weird isn't it? I thought that too.

Is the mechanism still easy to trigger at 850psi?

Not with a fully exposed piston, there is a bit of balance trickery going on to make this feasible.

Got a bunch of 3mm steel ball bearings, do you think they can be used to lock the dart?

Sure, that's what was used for the ballistic knife.

Nice work

Looks like it penetrates stuff pretty well, any muzzle energy figures?

Cheers not that much energy, the 8 gram projectile is doing just under 200 feet per second so around 10 ft lbs.

Had to bump this!

Jack i've been watching some videos from your channel...mind is blown..you've opened my eyes even further as to what pneumatics can do.

Love the head shots compilation footage!

But amazing work JSR..love those darts you make btw.

Cheers, appreciated