Welcome to the Inert Ordnance Collectors.
  • Login:
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 23
  1. #11
    Junior Member
    Join Date
    Apr 2010
    Location
    US
    Posts
    10
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by Tony Williams View Post
    I don't agree with that - APDS is spin-stabilised and such rounds are not called flechettes - that name refers specifically to fin-stabilised rounds where gun-fired ammunition is concerned.

    I believe that APFSDS is the correct designation for a fin stabilized 'penetrator', while APDS designation is used for rounds such as SLAP...am I correct?

    I have also seen APDS to more generally describe any AP round that has a sabot (to which the fin stabilised version would be a subset). Much like speaking about 'armor piercing' (AP) ammunition would include API, etc.

  2. #12
    Premium Member
    Join Date
    Mar 2009
    Location
    U.S.
    Posts
    4,523
    Thanks
    914
    Thanked 1,307 Times in 755 Posts
    Well, the SLAP round is an APDS, as it is designed to be an armor penetrator and the sabot does fly off once it leaves the muzzle, but the APDS design goes back at least to WWI 37mm projos, whereas the SLAP design is only around 25 yearrs old. APDS can further be divided into the type of sabot used, if it is a "pot" style or "petal" style, where the pot falls away behind the penetrator, and the petals peel off the side like a modern APFSDS-T Dart/sabot combination.
    ___HAZ/
    _____/ORD Hazardous Ordnance Recognition
    ________Saving Lives Through Education

  3. #13
    ORDNANCE APPROVED/Premium Member
    Join Date
    Feb 2009
    Location
    Michigan - US
    Posts
    3,997
    Thanks
    301
    Thanked 4,029 Times in 1,164 Posts
    Quote Originally Posted by Tony Williams View Post
    I don't agree with that - APDS is spin-stabilised and such rounds are not called flechettes - that name refers specifically to fin-stabilised rounds where gun-fired ammunition is concerned.
    I can agree that APDS should not be referred to as flechettes, in my opinion neither should their fin stabilized brothers. But what about the so called "mass stabilized flechettes" and the other similar finless items mentioned?

    I haven't seen any definition that requires fins, though admittedly they are more common - When you say " - "that name refers specifically to fin-stabilised rounds where gun-fired ammunition is concerned", this implies that there is in fact a formal definition? At least for small arms?
    All dug or live ordnance shown in my posts is under EOD control and has been or will be dealt with accordingly by EOD personnel

  4. #14
    Senior Member
    Join Date
    Jan 2009
    Location
    UK
    Posts
    1,500
    Thanks
    433
    Thanked 585 Times in 331 Posts
    Quote Originally Posted by US-Subs View Post
    I can agree that APDS should not be referred to as flechettes, in my opinion neither should their fin stabilized brothers. But what about the so called "mass stabilized flechettes" and the other similar finless items mentioned?

    I haven't seen any definition that requires fins, though admittedly they are more common - When you say " - "that name refers specifically to fin-stabilised rounds where gun-fired ammunition is concerned", this implies that there is in fact a formal definition? At least for small arms?
    I doubt that there is any formally agreed definition, but I've only ever seen the term "flechette" applied to small fin-stabilised anti-personnel projectiles. Of course, there are fins and fins - most of them stick out beyond the diameter of the body of the projectile (the most effective solution for accuracy), but some are kept at body diameter by thinning down the back of the body - in which case it can be difficult to distinguish between fin and mass stabilisation. I've never seen these used in small arms, though - only for convenience in packing them together in large-calibre rounds where accuracy doesn't matter much anyway because dispersion is useful, as long as they all head in vaguely the same direction!

  5. #15
    Senior Member
    Join Date
    Jan 2009
    Location
    UK
    Posts
    1,500
    Thanks
    433
    Thanked 585 Times in 331 Posts
    Quote Originally Posted by HAZORD View Post
    Well, the SLAP round is an APDS, as it is designed to be an armor penetrator and the sabot does fly off once it leaves the muzzle, but the APDS design goes back at least to WWI 37mm projos, whereas the SLAP design is only around 25 yearrs old. APDS can further be divided into the type of sabot used, if it is a "pot" style or "petal" style, where the pot falls away behind the penetrator, and the petals peel off the side like a modern APFSDS-T Dart/sabot combination.
    I wasn't aware that APDS was used in WW1. The first work on it that I know of was by Brandt in France in the late 1930s. This was transferred to Canada when France was overrun in 1940, and from there went to England where it was perfected (or, at least, made workable enough to be useful) for service entry in 1944, in the 6 pr and 17 pr tank/anti-tank guns. The UK remained the main user of APDS until the British 105mm L7 (arguably the first service tank gun specifically designed around APDS) became adopted as the NATO standard in the late 1950s.

    The tank APFSDS rounds were developed from APDS through following a logic chain which went something like this: armour penetration by solid shot is essentially a function of the energy delivered for every square millimetre of the penetrator's frontal area. Therefore, for any given weight and velocity, the narrower the projectile, the better it will penetrate. But the narrower it is, the longer it has to be, so you rapidly exceed the length limit for spin-stabilisation, which is roughly six times the diameter. Therefore it is necessary to switch to fin-stabilisation for the very long, thin APFSDS projectiles. If you're not using spin-stabilisation, barrel rifling becomes a nuisance, so it makes sense to use a smoothbore gun. The first in the field with APDSFS were the Russians, in the 1960s.

    The British (and Indians) are an exception in sticking to rifled 120mm tank gun barrels. They do this because they like to use full-calibre HESH rounds, which are more accurate with spin stabilisation. They get around the problem of the rifling destabilising APFSDS rounds by fitting the sabot with slip rings so the projectile isn't spun very much. There is a small loss in APFSDS performance, though.

    The SLAP rounds are just APDS which uses a plastic sabot rather than the original light-alloy type. Obviously the lighter the sabot the better because its weight just reduces the velocity of the projectile.

  6. #16
    Senior Member
    Join Date
    Jun 2007
    Location
    lincoln, England
    Posts
    1,957
    Images
    27
    Thanks
    857
    Thanked 580 Times in 216 Posts
    maybe fin stabilized rounds are older that you all think. heres a pic if a cannon from 1326 firing whats thought to be a metal dart.
    cheers, paul.
    Attached Images Attached Images

  7. #17
    Senior Member
    Join Date
    Jan 2009
    Location
    UK
    Posts
    1,500
    Thanks
    433
    Thanked 585 Times in 331 Posts
    Yes, I know - below is a picture of a full-sized model at the Artillery Museum. But a fin-stabilised round is not necessarily an APFSDS, just as a saboted round is not necessarily an APDS (crude wooden sabots were sometimes used in 18-9th century smoothbore guns).


  8. #18
    Junior Member
    Join Date
    Apr 2010
    Location
    US
    Posts
    10
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by paul the grenade View Post
    maybe fin stabilized rounds are older that you all think. heres a pic if a cannon from 1326 firing whats thought to be a metal dart.
    cheers, paul.

    They go back to nearly 10,000BC with the invention of the arrow, but the use of the sabot to use the larger caliber barrel to fire a subcaliber round is a far more recent technology.

    Is it perhaps safe to say that there is a LOT of ambiguity between flechettes and other items in terms of definition (similar to the gun/cannon analogy). In some cases it appears that they are near synonyms.

  9. #19
    Senior Member
    Join Date
    Jul 2008
    Location
    Germany (a civilian again!)
    Posts
    146
    Thanks
    4
    Thanked 9 Times in 8 Posts
    They may not be so similar actually- aside from the fins on modern models, there is a big difference in construction and mission.
    No one expects a small-arms or gravity propelled flechette to penetrate armor, and no one really plans on using 120mm APFSDS rounds against a single person wearing body armor....
    Flechettes also seem to be made pretty simply- a single piece of metal hammered into a sharp point with some integral fins.
    Penetrators are optimized for material density with metals like tungsten or depleted uranium- but, only in the penetrator portion, which usually has a dull, rounded point, protected by a ballistic windshield with a very sharp point, made of a softer metal, that acts like a "shock absorber" to prevent the hard material of the penetrator itself from shattering on impact with armor.
    Optimized design for hard-material defeat, compared to simple metal designs- maybe this, and the target intended is the defining point between the two.....

  10. #20
    Premium Member
    Join Date
    Jul 2008
    Location
    United Kingdom
    Posts
    4,451
    Thanks
    1,671
    Thanked 1,630 Times in 694 Posts
    Quote Originally Posted by E-tech View Post
    no one really plans on using 120mm APFSDS rounds against a single person wearing body armor....
    Now that would be nasty!
    Dave.

 

 
Page 2 of 3 FirstFirst 123 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Back to top