SpudFiles

Finally got this to work, this is the BBMG I intend to use in my sentry gun project.

Nothing remarkable about the design, it's a conventional vortex block fed with 800 psi from a HPA remote line, but the calibre is certainly the smallest ever, at least on this forum. As you can see from the video below most shots will go clean through sheet acrylic or the aluminium skin of a beer can, that might not sound like impressive performance but remember that it takes 70 of these tiny projectiles to make up the weight of one 0.177" BB

Here's the obligatory 420 fps video, holes appearing all over the place like some mysterious skin disease:

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A couple of pictures of the setup:



Basic components, vortex block and barrel, ball valve, paintball nipple and remote line.



The assembled layout, pictured with about 20,000 rounds of 1mm BBs (which can be bought very cheaply from eBay as "nail art" material)

Unfortunately, I can't get it to fire reliably, when it goes it goes but it tends to jam fairly frequently. My theory is that the barrel is a little tight and as the ammunition isn't exactly precision made, rounds tend to get stuck. I might have to find a way of sizing them through a piece of barrel tubing.

Did you get your quick disconnect from a airbrush? I have them on both of my brush's, 1/8th inch.

Nice work on the shooter. Is the barrel flaired? You can do that by using a cone shaped probe on a 90 degree angle through the air hook up. Might work...

on one hand it's cool becasue it's only 1mm calibre... but on the other hand... well how are you going to use it ? does it have enough range to reach 10 - 15 meters ??
I know that limited range was exactly what you wanted.. but don't you feel that your time could be better spent on something substantially more powerful
DAKA DAKA DAKA

anyway nice work as always...

Nice work jsr. That's really cool.

Impressive results for such "tiny balls"!

How consistent are the diameters of the balls?

Measure some randomly and determine the variability.
In particular the ones that jam.

You may have to presort as you mentioned. What a boring/time consuming job that will be!

JSR's go/no-go gauge for "Tiny Balls".

Oh also is tha aluminum foil that you are shooting at in the first part of the video?

That's just freaky....


planning on making a detent?

Did you get your quick disconnect from a airbrush?

Nope, eBay

Is the barrel flaired?

Yep, but I suspect some BBs are wider than the barrel

I know that limited range was exactly what you wanted.. but don't you feel that your time could be better spent on something substantially more powerful

There's always room for MOAR DAKKA! of course, but in this case it's just what I wanted, for reasons which I explained in the sentry thread, and some others

Impressive results for such "tiny balls"!

You can make up for small balls using high pressure

You may have to presort as you mentioned. What a boring/time consuming job that will be!

I was thinking the simplest and quickest way to do it would be to make a cone shaped attachment for the barrel and fill through the muzzle...

is that aluminum foil that you are shooting at in the first part of the video?

It's an opened up beer can, see below - I couldnt shoot the actual beercan because it would have made my location pretty obvious

planning on making a detent?

What do I look like, a watch maker

Here's a nice macro view of the damage, as you can see some BBs are still embedded in the various media:

Impressive damage, although i am still awaiting a pico hybrid of some sorts I bought some of those little metal bbs and was curious if they had tiny holes through them or if they were just solid little balls of steel? And what is the weight of 1 bb? I am interested because they seem suitable for high fps testing.

Mr.Sandman wrote:I bought some of those little metal bbs and was curious if they had tiny holes through them or if they were just solid little balls of steel?

Solid steel balls, 100 grams worth yours for just 10 bucks including shipping

I worked out the weight per BB should be around 5mg, meaning that you get 200 per gram, so they work out at 20 rounds per cent, where can you get a better deal I will take some BBs to work tomorrow and weigh them on the 0.00001 gram balance to get an actual weight.

Depends what you mean by high speed testing, with high pressures GGDT predicts some impressive velocities but it would be impossible to chronograph and even if you get it to supersonic velocities, the tiny mass will make it unlikely to be impressive as a single round.

jackssmirkingrevenge wrote:

Mr.Sandman wrote:I bought some of those little metal bbs and was curious if they had tiny holes through them or if they were just solid little balls of steel?

Depends what you mean by high speed testing, with high pressures GGDT predicts some impressive velocities but it would be impossible to chronograph and even if you get it to supersonic velocities, the tiny mass will make it unlikely to be impressive as a single round.

But a chronograph works with radio waves yes? In theory shouldn't it be able to detect even the slightest break in the barrier? I guess there is only one way to find out

Mr.Sandman wrote:But a chronograph works with radio waves yes? In theory shouldn't it be able to detect even the slightest break in the barrier? I guess there is only one way to find out

Most chronographs work with light sensors that detect the shadow of the projectile passing over two points over a known distance, in this case the shadow is negligible so it would be nigh impossible to detect.

jackssmirkingrevenge wrote:

Mr.Sandman wrote:But a chronograph works with radio waves yes? In theory shouldn't it be able to detect even the slightest break in the barrier? I guess there is only one way to find out

Most chronographs work with light sensors that detect the shadow of the projectile passing over two points over a known distance, in this case the shadow is negligible so it would be nigh impossible to detect.

Well then i have been misinformed, would there be any way of measuring its speed accurately without a chronograph? Or perhaps there is a special type of chronograph for smaller projectiles?

JSR;

I think you should order the SB07's.

JSR & the Pico "Blue Balls"

This could be your new trademark!

dewey-1 wrote:JSR;

I think you should order the SB07's.

JSR & the Pico "Blue Balls"

This could be your new trademark!

Haha quoted and sigged. Im actually quite fond of the SB03's myself, brass is such a nice color. Btw jsr where do you get your 3mm steel balls for penguns, i searched google and all i came up with is bulk bags of the stuff which i dont need.