What's going on in this pic?

Discussion in 'Shooting, Hunting and Fishing' started by EX_STAB, Jul 20, 2010.

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  1. [​IMG]

    Clearly it is a rifle bullet being discharged from a barrel but what is the barrel attachment?
    It appears to be some sort of muzzle brake but it looks as though the barrel is sectioned down the middle of it!

  2. It's one of them wotsits, isn't it?
  3. ugly

    ugly LE Moderator

    A moderator without the casing?
  4. I did wonder that. I think maybe the horizontal element is a longitudinal through bolt.
  5. I can't see it because of the web-sence nazi here at college. any chance of a bit more of a discription?
  6. ugly

    ugly LE Moderator

    Its definetly acting to bleed the gasses, my money is on some form of mod/flash suppressor!
  7. I'll send it by other means.
  8. Sympathetic_Reaction

    Sympathetic_Reaction LE Book Reviewer

    I'd suggest it is more liekly to be a suppressor than a muzzle brake as the gasses have very little if any rearwards component so as a brake are pretty useless.

    it's a bit complicated to tell what the bright area at the front is...I would suggest a bolt of some sort rather than the barrel, looks like there are other bolt points top and bottom of the suppressor, but the flash used to take the image effects which bits you can see.

    edit - on a second look there does seem to be a spiral dark area in the 'bolt' which does look like a section has been removed from a barrel following the grooves....but I can't think of any reason why you would do that.

    interesting shot though.

  9. Photoshopped snapshot of a suppressor in action?

    Thought at first they'd fired it with a perspex casing to show the innards, but since the rifling itself appears to be exposed, I'd guess its an edited photograph used for marketing purposes.
  10. Sympathetic_Reaction

    Sympathetic_Reaction LE Book Reviewer

    You reckon they have taken a dynamic shot and then overlayed an image of the cut out suppressor on top?

    I like the idea...could be true.

  11. Think you've got it
  12. Most brakes don't give any rearwards component, since that makes them Extremely Unpleasant. Like mine, which is a 6-Port fishgill break and a nasty bugger.
  13. My 2 p's worth is that it is a sectioned moderator as the bottom looks like it's there, it looks like it has a supporting rod/bolt added to strengthen the exposed side. Just my 2 p's worth.
  14. Biped

    Biped LE Book Reviewer

    I've got it pegged as already noted: A moderator without the casing, most likely photographed during firing in order to get an idea of the gas flow. There's many different moderator designs out there, using all manner of baffles, vents, ports and materials. This particular one (judging from the visible barrel tube) would appear to have venting in the barrel to allow the release of pressure into a suppressor chamber (missing from the photo) during acceleration.

    It might very well be a suppressor system that bleeds off sufficient gas during the expansion phase so that the bullet doesn't get accelerated to supersonic speeds, and thus is properly 'suppressed', as opposed to one where the bullet is already travelling at supersonic speeds by the time the gas hits the moderator and suppression occurs only of the gas pressure wave, still leaving the supersonic crack of the bullet.

    In the former of course, the effective range is massively reduced, but it's nice and quiet for assassination of the target, whereas with the latter system, the hearing of the firer is not affected too badly, the bullet has the benefit of maximum velocity for full effective range, but the intended target (and his chums) find it very difficult to ascertain the source of the shot as the report itself is still suppressed and they only have the crack to go on which tends to be omnidirectional when heard by human ears.

    I might be completely wrong of course.

    Edited to add:

    Photographing the gas-flow doesn't provide the best methods of analysing that which matters. A better way to do it would be to use sound frequency analysis as well as schlieren imaging of the gas and pressure waves as they pass through the baffling system. If you add that to a process of computerised fluid dynamics analysis that takes into account the absorbtion/reflection properties of various materials that the can, baffles and chambers are made from, you'd be getting somewhere.

    Schlieren mage of high velocity shot. Note the expanding pressure wave that gives us the 'report' of the shot being fired, ahead of which is the expanding pressure wave of the high velocity bullet. Most moderators deal only with the 'report', not the 'crack', about which you can do nothing if the bullet is supersonic.

    Schlieren mage of high velocity (supersonic) bullet in flight. Note the pressure wave that gives us the 'crack'

    As the pressure wave passes each baffle into the next expansion chamber it reduces further and the frequency changes due to cooling, reflection and absorbtion of the wave by the obstacles. A properly designed moderator (I don't know of one in production yet) would have an organic evolution of baffles and chambers that allow for that frequency shift and pressure wave adjustment at each stage, thus maximising the reductive potential of the system.

    You'll note that car 'silencers' work very well, and this is partly because they have a large volume inside the various cans and pipes to allow for cooling, absorbtion and mitigation of the pressure wave through repeated reflection to further that absorbtion. With firearms moderators, expansion volume for the gas is minimal, so you have to do it with baffles, vents, chambers etc. instead.
  15. There doesn't seem to be any gas being discharged towards the camera, which would have obscured the view.

    The silenced Sterling suppressor had a drilled barrel, in order to achieve a sub-sonic bullet with standard 9mm ammunition. The holes were drilled through the grooves in the barrel in order to minimize the 'cheese-grater' effect on the bullet.

    I'd think it is a suppressor in which the barrel has been drilled. For this photo, the holes facing the camera were plugged by fixing (brazing?) a piece of thin bar over the holes to stop the gas emerging in the direction of the camera.