by Saltner » Fri Feb 14, 2020 11:49 am
This ammunition is structured on a cylindrical case which has a considerable capacity.
As it is structured, the cartridge has a thermobalistic system that is built on a very subtle balance, which stands at the limit of what is commonly defined as "ball stop".
The term "ball stop" means that particular thermobalistic condition in which, at the moment of striking:
- the dust placed near the flash hole begins to ignite
- the pressure begins to rise
- the bullet begins to imperceptibly move forward
- moving the bullet forward causes the internal pressure of the cartridge case to drop sharply
- the combustion slows down dramatically until it almost stops
- the bullet stops at the level of the beginning of rifling
- combustion begins to resume
- the pressure rises again
- combustion progresses, positively influencing the development of the pressure - time curve, and the projectile begins to move slowly
- the combustion of the launch charge reaches a percentage of the original mass such that the projectile is accelerated inside the barrel, until it is expelled from
the same
The phenomenon just described, normally takes a few tenths of a second to complete, but can also take place in times of the order of a few seconds !!!
Anyone who has clumsily loaded the cartridge in question, has experienced on their own skin what it means to cause a ball stop.
In some cases, at the moment of the dog's fall, a dark noise is heard (also perceptible when wearing shooting caps), followed by the roar of combustion.
On the other hand, in other cases, no noise is heard at the moment of percussion and only after a few moments that seem interminable can the roar of real combustion be clearly perceived.