Build log for 1st High Pressure Pneumatic

[jackssmirkingrevenge]

I'm designing a new "Flat Top" Silencer, it will be fat on the bottom and WILL require a pod

Ah, you mean a bit like the AAC "Black Box" silencer



You'll need custom baffles but with your facilities it shouldn't be an issue.

Jack, my dear friend, you have, have you not heard the story of the german
.22 calibre rimfire that is SILENT apart from the click..

I'm not sure I know what you mean. I know the Russians have a lovely urban sniper in 22LR, the SV-99, while the Israelis use suppressed Ruger 10/22 for special operations - these days any 0.22 rifle with a decent suppressor is a virtually silent weapon.

For the ultimate in suppression though, the trick is to not let the propelling gasses escape at all - it requires some heavy engineering to keep everything in place, but it can be done - this patent shots the principle, basically the projectile is held in a sabot that is then blocked at the muzzle, meaning the projectile flies free while the sabot blocks the gas from exiting into the atmosphere.

[Novacastrian]

Yes just like that one except a flat top. I like the idea of using a full length silencer, i will probly go that way.
The rifle i mentioned had a full length silencer and the guy testing it thought it had mis-fired because he could not hear anything but the mechanism.
Thanx for everyones input

[jackssmirkingrevenge]

There's plenty of rifles out there with shrouded barrels, probably one of the earliest was the British DeLisle carbine of WW2, which is also off-centre, a design claimed to increase its effectiveness:



Here's some other examples:

[Novacastrian]

You have once again exceeded yourself, thanx mate.

Edit: That top one IS a strange design

[jackssmirkingrevenge]

It's no surprise when you consider how it was made. It's a combination of the stock and action from the 0.303 SMLE rifle, the barrel of a Thompson submachinegun and the 7 round magazine from the Colt M1911 pistol.

It's still reputed to be one of the most silent weapons ever made and was kept in service well after World War 2.

Valkyrie Arms manufacture a replica to the original specifications, and also offer an updated version with a folding stock, the Delisle 2000. I've also seen modern conversions in 44 magnum but as that's a supersonic loading I doubt it would be that quiet.

*ahem* yes, enough linkage, I should get back to work

[Novacastrian]

God damn that 2000 is a piece of engineering genius
If only.......

[Novacastrian]

I'm kicking this topic up because i have just finished my gun
JSR, i am not needing a equalisation hole no?
I have not tested it yet so cross your fingers for me. I will only be testing at 130psi because i have yet to purchased a shock pump

Edit: Photos later after work

Edit Edit: Disregard above i instead will be posting a pic of what happens when you try and remove a piston with 130psi (i tried a tighter piston) and blow some off the end of your chamber .

I fired at about 100psi (no guage) as the original piston seemed to have too much blow-by. Time for a new chamber!!

[jackssmirkingrevenge]

woo!

JSR, i am not needing a equalisation hole no?

Since your piston is a tight fit but not 100% airtight, then an equalisation hole won't be necessary

good luck with the testing

[Novacastrian]

woo!

JSR, i am not needing a equalisation hole no?

Since your piston is a tight fit but not 100% airtight, then an equalisation hole won't be necessary

good luck with the testing

Sorry JSR, see above

[jackssmirkingrevenge]

*blink* I don't get what happened

[Novacastrian]

The way i chose to retrieve the piston was to put 100psi down the barrel, and try to force it out the ass end (endcap removed) anyway, i put the blowgun in the barrel, pulled trigger and a sec later the piston came out alright, like at about 100fps, it managed to catch the thread on the end of the chamber just like a 14gram projectile would, it must have tumbled upon exit to allow this to happen, end result, chunk of pvc blown off.
Is that as clear as mud?

[jackssmirkingrevenge]

Fark! You could have poked it out with a bit of dowel y'know

How come it was jammed so tightly? Ideally the tolerance should be enough for you to move it with your little finger when it's lubed up.

[SpudUke5]

I cant wait. Is it going to be metal? Copper?

[Novacastrian]

The piston that did the damage is the green lfx one, It is 25.42mm in dia,
the one that i tested with was the teflon one at 25.34mm, there's only .08mm difference, i tried this because the teflon one was able to slide down the barrel under it's own weight and i thought that it might have been letting too much air past upon firing.
As for the dowel, yes but the air gun was right next to me- lazy bastard!!

Likeymy, the next chamber will be made of Aluminium i hope, the piston will be too- or Brass.

Edit: I just changed the above post for you JSR, to i chose to retrieve....

[Novacastrian]

Alright here are some pics, the damage to the end of the chamber, entire gun with the "offending" piston in the middle, view of end assembly- these are all "Exploded Views" ha ha.