How it Works: Single-Action vs. Double-Action

Whether you’re new to the world of handguns or a seasoned veteran you might have some questions about the different hammer-fired guns on the market. Before we delve into that, let’s do a quick refresher on how hammer-fired guns work in general.

Hammer-fired actions perform as the name suggests. When a hammer-fired semi-automatic gun is cocked a spring is compressed. As the trigger is pulled that spring moves the hammer, rotating it forward. When the hammer is propelled forward it strikes the firing pin which then strikes the cartridge’s primer, igniting it.

Revolvers are similar but have varied designs. Some manufacturers make their revolvers with firing pins located in the frame between the hammer and the uppermost chamber of the cylinder and others put the firing pin on the face of the hammer itself. Regardless of firing pin placement the end result is the same.

Odds are you’ve read through the specs on a gun and noticed there are different triggers available including single action (SA), double action (DA), double-action only (DAO), and a combination of the two (DA/SA).

Single-Action

Single-action guns require the hammer to be cocked before the gun is fired; a single-action revolver requires the shooter to manually cock the hammer before the first shot can be fired and for each subsequent shot as well.

Conversely, a 1911 needs only to have its hammer cocked once which can be accomplished by racking the slide. The semi-auto action of a 1911 then continues cocking the hammer automatically after each shot is fired until the gun is empty.

Double-Action

Double-action guns have triggers that both cock the hammer and release it to fire the gun. Because the trigger is performing the work of cocking the hammer prior to getting down to the business releasing the hammer for firing, the trigger pulls on these guns are long. (Sometimes they’re incredibly long trigger pulls.)

Some guns, a well-known example being the Beretta 92, can be fired either single action or double action, giving the shooter options. Others can only be fired one way or the other.

Perhaps the nicest double-action trigger I’ve run was on a Colt Python. The Colt Python is a masterpiece in and of itself – if you aren’t familiar with them you’re missing out – and they are hard to come by. The particular Python I shot had trigger work done by Grant Cunningham, a man with amazing gunsmithing skills.

Learning to master firing a double-action trigger can take time but is well worth the effort. Trigger control is a skill all handgunners should master and your skills should reach beyond the trigger of your personal gun.

I admit I have a love of good 1911 triggers. There’s just something about a beautifully put-together 1911 with a smooth, crisp trigger and a short reset. But I don’t spend all my time running single-action triggers whether on 1911s or revolvers; there are some fantastic double-action guns out there (such as my newest .44 Magnum double-action revolver for hunting). Broaden your horizons by learning to run a variety of guns. It’s both fun and an important skill to hone.

Now, if you’re wondering about striker-fired GLOCKs, that’s a story for another piece.