Hi Tony,
I agree - the spigot sticking out the front of a cylindrical, flat-faced projectile just seems all wrong, but it works, as the linked you provided shows.
In contrast to the M456A1's protruding spigot ,the 106mm HEAT rounds for the M40A1/M40A2 Recoillesss Rifle have a conical, hollow nose cap (as do the various Soviet Bloc RPG rounds). In the case of the 106mm HEAT round, the spin imparted by the rifling is only about 12 clock-wise revolutions per 100 metres, with flight stability provided by six fins protruding from the base of the projectile. These are housed within the cart case, and spring out after the round leaves the barrel. In this case, the MV of both the HEAT and High Explosive Plastic (HEP) rounds are about the same: about 503 m/sec for the HEAT and 498 m/sec for HEP. (HEP is the US equivalent to the Brit HESH).
Mike
|