AFAIK, S&W sights their guns for a center hold at 25 yards with standard ammo (for .45 ACP that is 230 gr FMJ). In other words at 25 yards, the bullet will strike right on top of the front sight when the top of the front sight is even with the top of the rear sight. The "6 o'clock" hold is for bullseye target shooting, not for a defense gun.
Jim
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