Muzzle Brake Identification

Discussion in 'History' started by Tigergunner, Jun 23, 2015.

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  1. Gentlemen,

    I wonder if anyone can identify the muzzle brake in the pictures shown. I believe it is from a 4.5inch gun but can not find a reference to it. The measurements are:

    Height 44cm
    Hole at threaded end, 17omm diameter
    Hole at muzzle exit 122-125mm diameter

    Serial number NG 82770
    NSN 015.99.964.5047

    I would be even more grateful if someone could identify which ship it came off using the serial number, if indeed it is from a 4.5inch. I have quite a good knowledge of land Arty equipment and am fairly confident it is not from a land piece.
    image.jpg image.jpg image.jpg
    Thank You
  2. Looks very much like a 4.5" Mark 8.
  3. Its a 4.5 Muzzle Break. Ive checked the NSN to confirm it.
  4. Thanks grog rat, I don't suppose you have access to a serial number database. The furthest I could get was it belongs to the Navy.
  5. It won't have been assigned to any particular ship or even any particular gun mounting. Barrels, along with muzzle brakes are changed at regular intervals. During its service life it may have moved from ship to workshop, on to another ship and so on.

    The only way to find it's service history would be to gain access to the Gun Memos associated with the ordnance.
    As the muzzle brake in the picture is not attached to the barrel, that would probably be quite a challenge.
  6. Ninja_Stoker

    Ninja_Stoker War Hero Moderator

    As a Stoker, I feel it would look nicer filled with about four litres of John Innes Number 3 with 'Mahogany Jewel' Nasturtiums grown from seed and 'Lucia Dark Blue' lobelia plugs in the upper flash suppressor apertures, placed in a sunny aspect. Feed regularly.
  7. (granny)

    (granny) Book Reviewer

    At first glance I thought it was the cowl from a chimney pot.
    • Like Like x 2
  8. Yep, Mk8, recognise the grooves in the end where we used to put greased cotton to form a cross. Used for alignment with the bore scope in the breach.
    If you look carefully you might see the marks from using a gert big length of scaffold to try and take it off after a shoot!
    Oh bugger, only 34 years ago since I last did that!
  9. Thank you for the replies, I thought is was from a 4.5 inch but had no evidence.
  10. Mod.1
  11. Topstop, funny enough that's the best picture I could find after scouring google for an hour, using every search term I could think of.
  12. Here you go Tigergunner. A fairly good pic of the muzze brake on HMS Cambridge's No.2 mounting with No.1 mounting firing in the background.

    cambridge2 (2).jpg
    • Like Like x 1
  13. And Cornwall still refused to surrender..........
    • Funny Funny x 3
  14. (granny)

    (granny) Book Reviewer

    I retired as MRCPOGI at HMS Cambridge in 1974. The Mk 8 was undergoing trials around that period. For the life of me I can't remember seeing a muzzle break on the mounting!
  15. Ninja_Stoker

    Ninja_Stoker War Hero Moderator

    One thing that surprised me during the Falklands campaign, was something that had never occurred to me - the barrels wear out and need changing after a few hundred shots are fired.
  16. Alacrity (my old gun, but I left the ship before the conflict) had to leave the FI because her barrel was 'out of life'. In the (para phrased) words of Skipper Chris Craig, 'I'll keep going until the bloody thing falls off!', in the words of MOD 'No!'
  17. 4.5" Mk8 barrel life is measured in thousands of rounds, not hundreds *. The exact figure may still be classified so I won't mention it here.
    Normally the opportunity for barrel changes can be planned into a ship's programme, refits, DEDs, (or whatever they're called now) and AMPs. In the case of the Falklands a much larger number of rounds were fired than would have otherwise have been expected between maintenance periods.
    A series inspection takes place every few hundred rounds - this does not normally require barrel removal but does involve MoD personnel crawling all over the gun.

    At HMS Cambridge we were frequently doing barrel changes because we were given the gash barrels that were approaching lifex. It made sense to get pusser's money's worth out of them and allow ships to have the 'new or nearly new' barrels to minimise the disruption to the ships' programmes.

    * Edited to add: I've just remembered that the earlier manufactured barrels had a life in the low thousands which may have been expressed in terms of 'umpteen hundred'.
    Last edited: Jun 25, 2015
    • Informative Informative x 1
  18. Granny, Im intrigued about this. The muzzle brake is designed to slow the recoil down, (hence the term 'brake'), by absorbing 50% of the recoil forces, with the recuperators and recoil cylinder absorbing 25% each and limiting recoil to around 15 inches.
    This assisted with reducing recovery time and allowed an increased rate of fire.
    Without the muzzle brake there would have been a catastrophic failure on firing involving the destruction of most of the working parts of the cradle.

    Having said that, as you say it was a trial period - maybe they were testing something I'm unaware of, (like the 'pack-back' firings on the 4.5" Mk6), although given the relatively flimsy nature of the alloys used in the elevating structure of the Mk8 I can't really see it happening.
  19. janner

    janner War Hero Book Reviewer


    Ballistic I think this was the type Granny was referring to

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