DAK Explanation
D-A-K, which stands for Double Action Kellerman. I found the following on a website called hipowersandhandguns.com, which will save me a lot of typing:
"DAK: The initials stand for "Double-Action-Kellerman" in honor of the man who came up with the idea. When the trigger is pressed on the DAK-equipped pistol, the hammer is cocked via a "leg" on the hammer that extends the distance between where the force is applied and the pivot hole of the hammer. This results in a much lighter trigger pull due to improved leverage. The DAK pull on a SIG P229 I measured is just over 6.5 pounds. While reset is nowhere near as short as the single-action 1911, it is not bad at all for real world use. In practiced hands, there is a shorter reset available. This results in a slightly heavier pull, but a shorter one. I am still learning this system and cannot use the shorter reset point with any kind of speed; I'm sure others can.
Though new compared to the conventional or selective double-action and certainly the single-action auto, the DAK system does seem to work. The Texas Department of Public Safety has used it for several years now; it seems to be easy enough for troopers to get the hits with and I'm finding no reports of chronic frailties within the system.
Speaking for myself, were I going to an auto strictly for protection and couldn't use a single-action automatic for whatever reason, at this point I'd cast my lot with SIG-Sauer's DAK pistols.
At this point in time, my only first-hand experience has been with a P229R in 9mm and a P220 SAS (SIG Anti-Snag) in .45 ACP. To say that I have been pleasantly surprised is an understatement. Though I favor the single-stack P220 in .45 ACP, the double-stack P229 in 9mm does have a smoother action, not by much but it is there. I have read that the double-stack guns generally do have smoother DAK actions but I am not sure that I understand why…not at this point anyway. What I do know is that if a person can shoot a double-action revolver accurately, he should be able to do the same with the DAK. Yes, they are that good in my opinion."
If you are new to DA/SA, and are buying a gun to carry for self-defense, I'd buy the DAK. It's unquestionably the most innovative "DAO" yet and is a much easier trigger pull to learn than DA/SA. It also forces a longer time between shots, which can be critical to a new shooter. Remember - EVERY round you fire in anger comes with a lawsuit attached.