[quote][quote]The CNCS bullets with the 4 plastics tails are for short range use. They splay out in flight to slow the bullet down and reduce range. I haven’t been sure of the significance of the tip color - cartridges with plain bullets also exist (I have one sectioned and will post a picture once I have time to scan the cartridge). It does look as though there are differences in bullet size and construction between the two examples you show and the one I have. This suggests that the tip color was used to identify bullet types.
[quote]Dave, the material is way too hard to splay out or change it’s shape in any way during flight. Also would this contradict a use with flash hiders or muzzle brakes.
The sections between the flaps are shaped with one rounded side which is influencing aerodynamics in a way where it is acting against the projectile spin and sowith is reducing the spin rate. This leads to a loss of stabilization and subsequently will make the projectile tumble and loose speed/range.[/quote]
When I was told of the splaying action, I assumed that the heat and force generated in firing the cartridge would be sufficient to affect the tails. You do raise a good question about use in rifles with flash suppressors or muzzle brakes. If the tails remain in the unfired form, what is their purpose? Improved bullet stability but if so why? It’s worth noting that Belgium short range bullets (CNCS, similar bullet profile and weight) without tails exist.
Dave and Alex, the original design from 1965 was supposed to have flexible flat tongues that splay out under the action of centrifugal force and thus increase the resistance of the projectile in the air. I don’t know if a projectile of this type was made.
Regarding the different colour tips and projectiles types found in these short range cartridges, I can confirm the identification of at least two variations taken from original boxes (sorry, I don’t have these at hand to take pictures):
- Plain tip, NATO symbol FN-72 headstamp: muzzle velocity, 1300 m/s, maximum range 1000 m.
- Light green tip, NATO symbol FN-72 headstamp: muzzle velocity 1100 m/s, maximum range 400 m.
Those two seems to be the only standardized models, as both are mentioned in a c. 1978 catalog.