This is called “4+1 syndrome” and is widely documented. It occurs with semiautomatic pistols (and to a lesser degree with semiautomatic rifles) when the first hand-chambered round puts the parts in a very slightly different firing alignment, or “battery,” than what they go into during firing when the mechanism cycles automatically and auto-loads each subsequent cartridge. Interestingly, the standard Beretta 92 in 9mm does not seem to be particularly prone to this, certainly not to the degree I saw in the test sample of Beretta’s .22 conversion unit.
