shut-off valve suppressor

[wyz2285]

I love this idea, won't work for me through, because I use bbs and my barrel bore is 6.1-6.2 mm ID witch means it's not air tight and the air will reach the barrel side port before the bb, and blocking the barrel. And I agree with Al-gx, I don't think the blocking ball bearing will be pushed by the air, unless some modification to the barrel side ports to increase the air flow to the suppressor chamber.

[jackssmirkingrevenge]

So...please JSR...wip up a quick prototype to end the discussion..

By the end of this weekend, hopefully

Yeah but that would only be significant after the projectile has left the barrel and the air can rush out, it seems the drawing intends that to happen a lot sooner.

In my experience with seal detent BBMGs, it's possible for a BB to get stuck in the detent before the previous BB has even left the muzzle, this is what I'm hoping for - near instant sealing of the port as soon as the projectile has passed.

What would the end plug be made out of epoxy?

won't work for me through, because I use bbs and my barrel bore is 6.1-6.2 mm ID witch means it's not air tight and the air will reach the barrel side port before the bb, and blocking the barrel

I don't think that will be the case. Look at BBMGs, they all have a minimum flow before the BBs are agitated and start to fire - so I'm quite confident that both the column of air pushed in fron of the projectile and any small leakages past the projectile will not be enough to move the blocking ball and cause a catastrophic failure.

Anyway, the proof of the pudding is in the eating, so I'm currently making a generic hybrid "test chamber" (using the "machined and epoxied endcap" technique, as the "poured epoxy endcap" always seems to develop leaks over time with the repeated stress of hybrid firings...) and a prototype of this system will follow shortly.

[wyz2285]

good point, the air before the projectile probably will exit from the muzzle instead of pushing the ball, but this suppressor would only be safe to use for base mount cannons.

[Zeus]

You know, I really doubt it would be unsafe, all that can happen is a fairly slow (subsonic) projectile hitting a plastic ball. If it's made out of ABS or delrin, it won't fragment.

And the porting can be tuned, by opening up the holes, or the location of the holes can be adjusted to trigger the ball at the right time. There's heaps of variables which can be adjusted.

Also, rubber "bouncy balls" might work well too.

[wyz2285]

I have fired a 0.25g BB to supersonic, after making a hole in a steel can, it hits the wall and became a "pizza" instead of a BB
So I don´t want this happen inside of the suppressor, it will break the end cap. For subsonic shooting, a normal suppressor is enough for me

[MrCrowley]

Inspired by this thread, I've come up with my own, simple, hybrid suppressor that so far has worked wonders. You could fire a hybrid in the middle of your work place and your boss would barely hear the mouse fart this thing produces.

I'm just glad Jack can start building large bore hybrids now that I've gone and sorted out his noise restriction problem...
[youtube][/youtube]

In all seriousness, I'd love to sacrifice a barrel by drilling a bunch of holes in the end of it and inserting it through a watermelon with the muzzle just pointing out of the side.

Edit: I did get in a bit of trouble with my neighbour, she was gardening behind a shed and I hadn't noticed her otherwise I would have postponed it until she had left. You can hear all the pieces hit her roof and I even found the top of the melon about 20m away in our car port.

[battlelava]

What would the end plug be made out of epoxy?

I was thinking it was to be milled from a block of aluminum, more durability (something I'm to use to requiring to have as I will break everything) If the ball gave it a full seal how much pressure would be applied to the internals (inside the silencer), enough to cause any damage?

[Brian the brain]

@ MrCrowley:

Wonderful! Where did you find a watermelon that fit the barrel so well and how many times can you use it??


Do they sell them online?
Did you measure the noisereduction?

[jackssmirkingrevenge]

hehe nice one MrC

Prototype curing, some preview pics below. There's no chamber, and I made no effort to make it seal completely.

[Brian the brain]

Jsr rapid prototyping saves the day!!!


Hmm...it has very little volume...

The idea of having extra volume is : the expansion of the gasses makes for a lower pressure..
Wich would put less strain on the materials used.

If your material is up to the task this prototype might be even better!
Super short and hopefully very effective!

If not...I blame lack of sufficient volume anyway..

Thanks for trying this out in real life J.
This could be a major improvement for all..

Although I was expecting the device to be at the end of the barrel..
Or wait...Am I looking at a hybrid chamber with the shut-off at the beginning...or is that the other way around and is there a conventional silencer with the device at the base of it?



damn..I'm confused now..

[Gun Freak]

Looks nice. Did you make that screw? I think the small volume won't be an issue, because you used strong materials. Plus it will really test the concept.

[jackssmirkingrevenge]

If your material is up to the task this prototype might be even better!

Read on

Although I was expecting the device to be at the end of the barrel..
Or wait...Am I looking at a hybrid chamber with the shut-off at the beginning...or is that the other way around and is there a conventional silencer with the device at the base of it?

The last picture is the hybrid chamber.

Did you make that screw?

Yup, delrin.

Anyway, test number one at 8x, BANG!!!!

hmmm...

The concept seems to have worked though. The projectile flew out unhindered and the BB blocked the muzzle as intended. The problem was my usual under-engineering, the PVC body couldn't take the pressure and the bottom blew out of it, something a big more heavy duty is required - still, the theory seems to be sound

edit: further investigation suggests the projectile was affected, more pics attached... a bit of lead has been deposited on the end of the barrel, and the projectile itself didn't penetrate the backstop as much as one might expect, and is more deformed.

[Fnord]

You might have to bore out the last bit of barrel if you think it's deflecting somehow. Does the airsoft bb show signs of being hit? it could have been sucked into the path a bit due to issues already discussed

Going to hijack this briefly;

Inspired by this thread, I've come up with my own, simple, hybrid suppressor that so far has worked wonders.

So, listen up all you Americans! Anyone found possessing a watermelon without the proper license will be found guilty of a felony that carries a 10 year minimum sentence. Isn't US law great?

But, as far as I know NZ has no laws against possessing a silencer.

[jackssmirkingrevenge]

You might have to bore out the last bit of barrel if you think it's deflecting somehow. Does the airsoft bb show signs of being hit?

Haven't found the BB yet

Speaking of which, was it you who had suggested vaguely similar idea by PM a couple of years ago?

[POLAND_SPUD]

no idea if it was him but that's a rather obvious solution to the problem don't you think?