PAC 120 Bar - 1700 PSI

[Petitlu]

oui au même niveau, aucun épaulement.
yes on the same level, any shoulder

I modified the gun by welding above a sleeve 1/2 BSP.
J'ai modifié le canon en soudant un manchon de 1/2 BSP.



With bullet :



With out bullet :

[Petitlu]

hi
here the continuation of the transformation of my PAC 3000psi into bullpup.









There, the brass connections are temporary and will be replaced by connections high pressure




Your screw?

[jackssmirkingrevenge]

Much better, nice and compact - and I see you've gone for a more reasonable chamber size. Just needs a decent butt plate, scope mount and maybe a bipod - plus of course a full length integral suppressor are they legal in France?

[Petitlu]

Thank you

decent butt plate is envisaged, the PAC is not finished.
For the regulator of sound it is not interdict in France but difficult to realize...
An idea?

[jackssmirkingrevenge]

For the regulator of sound it is not interdict in France but difficult to realize...
An idea?

The easiest would be a tube over the barrel, and some ports at the muzzle end:



Still, I wouldn't want to drill holes in a lovely barrel like that.

Maybe something like this?

[Petitlu]

really very interesting, it is an idea to be explored.
Thank you

And would the sound be very reduced?

[jackssmirkingrevenge]

And would the sound be very reduced?

Have a look at this, I made it for a commercial HPA air rifle - the difference in sound is quite impressive, most of the noise from the air blast is removed.

Remember, you are using a lot of air at high pressure, so a large volume is very important.

[Petitlu]

very pretty realization!
But won't the high pressure explode PVC?
Is what the power decreases?

[jackssmirkingrevenge]

But won't the high pressure explode PVC?

If the PVC has high volume, the high pressure air has a lot of space to expand to so the actual pressure in the suppressor will be quite low.

Is what the power decreases?

I did a test with my Daystate Mk3 with and without the Airstream silencer. In between strings I refilled the rifle to the same pressure. Here are the results in feet per second:

First, without silencer - 860, 860, 870, 869, 872 (866.2 average)

With the Daystate airstream CF silencer fitted - 877, 880, 884, 882, 883 (881.2 average)

This gives an average increase in velocity of 15 feet per second with the silencer - in practical terms, an insignificant increase, which you'd never notice without a chrony, but interesting nonetheless.

[Petitlu]

excel!
it is certain that I would make a silencer, surely removable
Today I make the support of glasses
Thank you

[Mimikool]

JSR use lot of epoxy, but for your case it may be to brittle for the pressure you use.

To have a efficient silencer, in theory, the lenghts of the barrel and the silencer are the same. But you could have any reduction of noise with smaller silencer i think.

And with it, you have to make a bipod, because it will be very heavy, the weight will be concentrated on the front of the cannon.


Je ne suis pas sur que l'époxy soit la meilleure solution dans ton cas, sa résistance est assez limité, même pour un silencieux je tenterais pas. C'est 12bar maxi avec cette résine sur le fofo.

Un silencieux efficace doit au moins faire la longueur du canon pour être efficace en théorie, mais tu aura deaj de bon résultat ave cun peu moins long.

Il te faudra un bi-pied ou support obligatoirement, ce sera lourd et le poids sera concentré sur l'avant du PAC.

[Petitlu]

the PAC is in bullpup now thus better distribution of the masses
If I put at it a silencer it will be over the length of the gun and not attached at the end of the gun thus the weight will be less

le PAC est en bullpup maintenant donc meilleure répartition des masses
Si j'y met un silencieux ce sera sur la longueur du canon et non attaché au bout du canon donc le poids sera moindre

[Mimikool]

Mais il sera bien moins efficace, ce qui comte c'est la quantité d'air qui entre dans le silencieux avant que le projo sorte complètement du canon+silencieux.
Dans cette config' le projo sortira trop tôt, l'air n'aura pas le temps de passer par les trous du silencieux et va préférer passer par la bouche du silencieux, en suivent le pojo.
Ca marchera, mais moins.


But it will be less efficient, it's the quantity of air whitch go on the silencer by the holes before the bullet leave de barrel + silencer completly.
In the configuration, le bullet will leave the barrel too early, the air will not have the time to go in the silencer, and it will prefer follow the bullet and leave the barrel with it.
It will work, but less.

For the regulator of sound it is not interdict in France but difficult to realize...
An idea?

The easiest would be a tube over the barrel, and some ports at the muzzle end:

In the first diagram, i thinks if the holes are closer the muzzle of barrel it's better, the air will ahve the time to enter in silencer chamber, while the bullet continue its travel in silencer internal pipe.

[Petitlu]

ok
not obvious all that…
I will see later, for the moment I must finish the PAC to be able to draw.
I expect the HP connections impatiently

[Petitlu]

Continuation :
I received the HP connections: