Air speed behind the pellet

[kevingambrell]

Just out of interest does any one know if the air columb behind a pellet goes above the speed of sound as the pellet exits the bore?
Im trying to see a good reason to machine an air stripper and the only one I can see is the air exceeding the pelet speed as the pellet exits the bore.
Its seems obviouse that all the stored energy in the air isnt expended as the pellet exits but im wondering if its still expanding at a high enough rate to push its velocity
up above that of the pellet.
I cant help but think im missing something here if air strippers are to work.

[Andy-K2]

Hi.. As far as I'm aware its the projectile that breaks the sound barrier and not the air behind it. My reconing would be that a subsonic powder fed projectile would exit the barrel less than 1,127 ft/s thus not breaking said barrier nor does the following air escaping would do the same so no "sonic crack".
I hope this gives you something to ponder over Is it an air strippers to just reduce recoil by letting the air escape in a phase rather than a rush at the barrels end? If so I figure they are of no use on an air rifle, as are purely cosmetic unless of course we can have a 50cal with a 7ltr air tube Now were talking

[raygun]

What makes the "crack" on a PCP if it's not the pellet ?

ATB
Ray.

[Kev Todd]

What makes the "crack" on a PCP if it's not the pellet ?

ATB
Ray.

Dieseling.....

[poguemahone]

What makes the "crack" on a PCP if it's not the pellet ?

ATB
Ray.

Dieseling.....

and hard hitting hunting pellets with their extra knockdown power

[raygun]

What makes the "crack" on a PCP if it's not the pellet ?

ATB
Ray.

Dieseling.....

ATB
Ray.

[Andy-K2]

I don't get a "crack", must be because I shoot a Weihrauch

[kevingambrell]

Well after giving this some thought as I poo picked the horse field.

One point I had missed out was the compressed column of air in front of the pellet. As the pellet travels up the bore under a massive acceleration this column of air has to become slightly compressed and warmed slightly. My thought is what effect does this turbulent air have on the pellet as it passes through the expelled air? Come to that is this how air strippers work, not on the air behind the pellet but on the air in front.

Next up is the fraction of a second after the pellet exits the bore. If you imagine freezing the pellets motion maybe 50 thou out of the bore and letting the air continue to escape. You have in effect created a venturi all be it annular in form, so from this its a dead certainty that for all be it a fraction of a second we have air possibly approaching the speed of sound and very turbulent. With this in mind I am more convinced air strippers are possibly snake oil.
Come to that if the first portion of the stripper is above bore diameter you may be increasing the duration of the venturi effect.

[Aitch]

I was always led to believe that air strippers were designed to remove the turbulent air from in front of the projectile,
And in the absence of knowledge who am I to argue?. I was also told that because of the design of the air stripper on my Steyr the expelled air was deflected to the side and backwards, therefore making a much louder bang and frightening the Bejeevers out of the people next to me on the range.

[gary martin]

cracking thread, no pun intended.