The specifying of pistol shot is a term of art for the relative position of two vessels (seen frequently in descriptions of 'close engagement') - that this seems to refer to 400 yds casts a new light on the interpretation of these 'close in fights' - this being at roughly the range of double shot pointed by the line of metal, or single shot fired "at" the horizon (ish).

Musket shot and 'half gun shot' are given as being the same, which would reasonably be ~3 cables or ~600 yds, which is roughly the line of direct pointing with the distant charge, and gun shot would then fall at roughly 1200 yds with a superelevation of between 2 and 1.5 degrees (RN/Fr pattern heavy guns).

The diminution of charge and use of double shotting at shorter ranges gives a fairly 'flat' effectiveness between 300 and 600 yds (or 400-650m for the French patterns - which throw somewhat higher and thus have a lower effect when they arrive further out - a 36 livre gun "points-like" a 24 pdr, but is closer to a 42 pdr when outside the ranges of direct pointing. French point their lighter guns to a shorter distance - English use longer guns and higher elevation to try to stretch their light guns further (though with a diminishing of the effect).