That is SAAMI. The way I was explained was that you can use faster burning powder than normal if you load longer. Faster burning powder has less recoil but creates higher pressure. You can only do that with a fully supported chamber in some pistols designed for competition( STI - SVI 2011s) with mags capable of taking the longer rounds. For example one GM I know was using Clays with a 1.225 OAL.
But my other point is that VihtaVouri recommends 1.126" OAL for all of there load data including for N320.




















































