m1911a1 問題

To explain this simply:

Double action (DA) (雙動模式) = 長板機
Single action (SA) (單動模式) = 短板機

Because in double action mode, you need to pull the trigger for a longer distance to raise the hammer and compress the spring before the hammer is released. In single action mode, all you need is a just small movement of the trigger to release the hammer.

This is true for both revolvers and semi-automatic pistols. The m1911 was designed back in 1911 (actually earlier) before double action was invented, therefore it is a Single-Action-Only pistol.

2007-04-20 08:47:44 補充：
I meant, the m1911 was designed back in 1911 (actually earlier) before any double action semi-automatic pistol was invented. There were many double action revolvers at that time.

因為這手槍的板機是特別設計的。