An officer's sword and pistol

In the mid-to-late 18th and across 19th century (with a bit of bleed-over into 20th century) military officers tended to have both a sword and a pistol. The sword slung from the left hip and the pistol tended to be secured on the right hip. In the early days officers had one or two muzzle-loading pistols (shortened to ML for the rest of this post) be it flintlock or caplock depending on exactly when. Around the 1850's revolvers came in vogue but were not initially universally issued. Among many of the arguments in favor of one type or the other include the debate between ammo amount versus power. Revolvers at this time were also criticized for jamming frequently. The sword was still used in combat at this time but slowly fading into pure ceremony and was used to point out directions and commands. In a scenario in which the sword is already drawn for whatever initial reason, the ML pistol has one additional advantage over revolvers, the draw.

Revolvers were often secured in a closed pouch with the grip on the right, which is fine for if the right hand is unoccupied (all this assuming right-handedness). If the sword is out to command or to defend quickly, drawing the revolver is very inconvenient (especially if the sword knot is not being worn). One has to either let go of the sword to grab the revolver then switch hands to get the sword back or twist the left wrist awkwardly to draw the revolver. One last option is to wear the pistol on the same side as the sword, but that causes imbalance and restrict the draw only to the left side (comfortably). The same applies to later semi-auto pistols but this post is more about the general transition from ML pistols to revolvers.

While oriented to the right like the revolver, the ML pistol was either stuffed into or clipped onto the sash or belt. These pistols tended to have a more elongated grip as opposed to the sharp angle of revolver grips (unless they were the distinct German styles). Because of the openness and the lightly curved grips, drawing this pistol would be much easier. The closest analogy is that of a samurai drawing his wakizashi while already wielding his katana which was closer to the center of the body like many ML pistols were. Lastly, ML pistols tended to be marginally lighter than revolvers which allows more comfort being worn on the sword side especially because the can have the same orientation on said side as the right.