The double-action revolver is so named because a single press of the trigger performs two functions:
1. Moves the hammer rearward and,
2. Releases it, firing the gun
The vast majority also have single-action capability. In other words, the hammer can be manually cocked so that a lighter and shorter trigger-pull discharges the weapon. It is generally believed that this allows for more precise shooting, perhaps at a greater-than-expected distance.
Do we need or even want both on a defensive revolver, particularly a compact snubnose?
Opinions vary on this question so let’s examine this area in more depth.
Folks wanting conventional DA/SA capability on their defensive revolver usually cite wanting to be more able to make a very precise (head) shot in the event of a hostage situation or if firing across a parking lot. They also like the idea of thumb-cocking in an emergency should a slightly high primer be causing the cylinder rotation to “drag”.
Shooters preferring double-action-only can argue that the longer, more deliberate trigger-pull necessary to discharge the revolver, makes is less likely that an unscrupulous attorney would try to claim that they cocked their deadly weapon and then “negligently” shot his criminal client. Older shooters as well as law enforcement officers trained on the wheel gun frequently prefer DAO. With proper training, double-action defensive revolver shooting can deliver very effective results.
Nothing in this world is for certain, but I’ll cast my lot for the DAO snub with a bobbed hammer if carried via a pocket holster and the same for the revolver that’s to be carried inside-the-waistband, regardless of barrel length. If it’s being carried in an outside-the-waistband holster, I still prefer DAO for self-protection but am ambivalent about the hammer spur being removed or not.
My choice does not necessarily have to be yours. If you already own or simply prefer a double-action revolver that also retains single-action capabilities, no problem here but I strongly suggest learning to shoot it double-action for defensive purposes.
Though nothing actually requires it, many DAO revolvers with exposed hammers have the spur removed or “bobbed”. The idea is that the spur is unnecessary as the revolver cannot be manually cocked so why leave it there to possibly snag on clothing if carried concealed?
Can revolvers still having single-action capability have their hammers bobbed? Sure, but I’d treat them as though they were DAO. That said, some folks have revolvers just that way, some having the tops of the bobbed hammers serrated for (somewhat) easier lowering from the cocked position. In the past, I have had such revolvers. Normally, I don’t get nearly so wrapped around the axel with lower cocked hammers over live rounds as do some. Yes, it requires one’s full attention and the potential for an accidental discharge is present, but it is just not as difficult as disarming say a live atomic bomb as in “Goldfinger” if the spur is present. Remove it and I do believe that the potential to inadvertently fire the revolver goes up considerably. Certainly, the reader should make his/her own decisions on this matter, but my bobbed hammers are on DAO revolvers.