It is known that 8000 Colt Single Action Army revolvers were purchased under the Army contract of July 23, 1872, all of which were shipped to the Springfield Armory between November 25, 1872 and March 18, 1874. One thousand of these were shipped to the Rock Island Arsenal earmarked for the 7th Cavalry. Prior to the Black Hills expedition, some 755 of these were issued to the 7th Cavalry.
The chart below shows the estimated serial range of the 8000 revolvers of the Army contract of July 23, 1872. Attention "Lot 5".
Lot 1 -- 1000 revolvers, estimated serial numbers 200-1222 received Springfield Armory November 28, 1873.
Lot 2 -- 1000 revolvers, estimated serial numbers 1223-2336 received at Springfield Armory December 19, 1873.
Lot 3 -- 1000 revolvers, estimated serial numbers 2337-3437, received at Springfield Armory January 3, 1874.
Lot 4 -- 1000 revolvers, estimated serial numbers 3438-4515 received at Springfield Armory January 24, 1874.
Lot 5 -- 1000 revolvers, estimated serial numbers 4516-5521, received at Springfield Armory January 31, 1874. (From this lot 755 revolvers were issued in late June, prior to the Black Hills campaign to the 7th Cavalry.)
Lot 6 -- 1000 revolvers, estimated serial numbers 5522-6530, received at the Springfield Armory February 17, 1874. (Although shipping records are incomplete, it is almost conclusive, some guns from this range were issued to the 7th Cavalry for Companies D and I, which included turn-ins from Company K.
Lot 7 -- 1000 revolvers, estimated serial numbers 6531-7540, received at Springfield Armory, March 5, 1874.
Lot 8 -- 1000 revolvers, estimated serial numbers 7540-8610, received at the Springfield Armory, March 18, 1874.
While it is virtually impossible to positively place any Colt Single Action Army (except three) directly in the battles of June 25-26 1876, there is information available from which we can narrow down the possibilities. We know, of course, that Custer's 212 men from company C, E, F, I and L of the Seventh Cavalry were lost and all their firearms taken from the field by the Indians. There are only three revolvers that have been positively confirmed as being with Custer. Not surprisingly, two of these were recovered from Indians and a third was excavated from the field in 1933.
Reno lost 40 men and their revolvers. Benteen lost three men but recovered their revolvers.
Of the total compliment of 632 troopers, staff and scouts, 266 were killed and between 252-300 of the original 755 Colt Single Action Army revolvers were lost.
After twenty years of hard service, virtually all of the Seventh Cavalry's Colts were recalled. Between 1896-1903, These "Custer Colts" were among 14,900 revolvers that were refurbished and cut to 5-1/2 inch barrels at Springfield Armory and Colt. The vast majority of these Artillery models will feature mixed numbered parts.
The chart below from John Kopec's "COLT CAVALRY & ARTILLERY REVOLVERS.... a Continuing Study" lists the known examples of Colt Artillery models from the Seventh Cavalry's "Lot 5" serial number range.