Fairly new to the group, but learning more with every thread I read. Question for ya'll - I just purchased a Taurus PT111 Millenium Pro, 9mm. Now, I've read about those being available in both Double Action Only and Double Action/Single Action. I have a rudimentary understanding of what that means, basically that DAO is a heavier trigger pull every pull, but DA/SA is a heavy first pull, lighter followup. (That's right, right??) But I'm curious as to how exactly the two systems work (only owned revolvers previously), pros & cons of both systems, etc, and how to tell for certain which I have. Have only had the chance to run a few rounds through it, and really couldn't tell for certain. Thanks for any info and opinions..!