"Standard Steel/High Performance Steel ammunition and proof chamber pressure.
CIP sets two levels of chamber pressure for steel shot classification and proof: Standard Steel Shot and High Performance Steel Shot. The Standard Steel Shot has a maximum average pressure of 740 bar (10,733 psi). This maximum average is below the limit for all 12 gauge shells (11,500 psi) in the United States – lead and steel. The proof level for Standard Steel Shot, 1,200 bar (17,405 psi) is also below the proof level of all 12 gauge guns (lead and steel) in the United States.
The High Performance Steel Shot has a maximum average pressure of 1,050 bar (15,229 psi). This maximum average is significantly higher than all 12 gauge shells in the United States – lead and steel, even including the new 3-1/2” loads. The proof level for High Performance Steel Shot, 1,370 bar (19,870 psi), actually falls right in the middle of the United States proof load specification (19,000 to 20,500 psi). Note that from a SAAMI standpoint, this CIP High Performance proof level is low for the actual working pressure of the service loads (see Diagram 1).
Maximum Velocity
CIP sets a maximum velocity for each of the steel shot levels; 400 m/s (1,312 f/s) for Standard Steel Shot, and 430 m/s (1,410 f/s) for High Performance Steel Shot. SAAMI has not limits on velocity. Since chamber pressure is established at time of loading, for ANY shot weight load, the stress on the chamber applied by the cartridge is established and controlled. In studies conducted over the last 25 years, it has been found that stress to the choke and choke tubes will generally increase with velocity. However, the amount of stress is actually controlled by the complete cartridge system, most importantly the steel shot wad design. From a SAAMI/United States perspective, velocity is independent of chamber stress as long as the pressure is controlled properly, and damage to choke tubes cannot be controlled by velocity alone since wad design is the significant controlling parameter."
Altså, om leirdueammoen går med over 400m/s så er det en "high performance" ladning. High performance ladning har som trykkgrense 1050 bar, mens standard ladning (som har maks hastighet under 400m/s) har maks trykk på 740 bar..
Har jeg lest og tolket dette riktig?
Jeg har hentet ifo fra denne siden: http://www.dpi.vic.gov.au/game-hunting/ ... d-proofing" target="_blank