I have come across markings on the Russian 107mm M1877 siege gun that I find somewhat puzzling. The 107mm M1877 displayed in Finland is dated 1884 but is marked "CA". This is generally used to abbreviate Soviet Army and in fact the sign giving information for the gun mentions that CA is "Soviet Army". I also know of other 107mm M1877 guns in the United States marked with "CA" but only having dates consistent with Imperial Russian Service.
Any idea what else "CA" stamped on an M1877 Breech-ring could stand for?
Does anyone have good photographs or tech drawings of the breech for this gun?
(note the photos are re-posted from various Russian Language web fourms and sites)