Your needed primary source for your question is found in NARA collection RG156.

"Entry 215 is described as "Abstracts of Army Officers' Reports on Small Arms and on Accoutrements and Horse Equipments, 1863 - 64." These abstracts consist of two volumes, but the one that deals with accoutrements and horse equipment is almost entirely blank. The second volume contains a wealth of observations on the efficiency of many types of small arms, including the Starr carbine. Page 145 names eleven officers of the First and Second Regiments, Colorado Cavalry, in the second quarter of 1864, who say: "These officers agree that [Starr carbines] carry well, get out of order very easily, the locks break most often, prefer large Cal., and that they are not sure fire, and are poorly made."

See http://www.archives.gov/publications/prologue/1995/winter/civil-war-arms-and-equipment-2.html

John R.