You’re really close, Russ T. There were three nearly back-to-back engagements. The first one, which you have identified, involved Fetterman, and became known as the Fetterman Massacre. This was followed by the Hayfield Fight (see second paragraph below). The one we are looking for is the last of this “trilogy” of fights with Red Cloud.
“The task of fort building proceeded regardless. The first taste of Red Clouds fury came at newly built Fort Phil Kearney, when brash Captain William Fetterman who claimed that with 80 men he could subjugate the entire Sioux nation was wiped out along with the 79 men under his command. When a group of wood cutters were caught outside of the Fort, Fetterman rushed to their rescue. Despite the clear warning from his superior, Colonel Carrington, not to pursue the Indians, Fetterman did just that. He golloped after the feinting Indians into the Lodge Tail Ridge and out of sight of the Fort. Over the hill Red Cloud waited with the main force of warriors. They streamed upon the hapless Fetterman destroying the eighty men whom he had so proudly bragged that he could wipe out the Sioux nation with. The Fetterman massacre was the armys worst western defeat up to that date. The only thing that stopped the entire fort from being overrun was the terribly bad weather. The Forts commander, Colonel Carrington, sent out a scout on a perilous, frozen bid for help. After a heroic journey this scout he reached a telegraph wire at Horseshoe Bend where it was possible to contact Fort Laramie and call for help. However the message did not get through. The courier, Portugee Philips rode on, finally able to get to Laramie. Reinforcements were rushed to Fort Phil Kearney. Red Clouds warriors quickly dispersed.
“On August 1st Red Cloud came back. This time he attacked both Fort Kearney and Fort C F Smith. About 500 Cheyenne warriors came across 30 civilian hay cutters about two miles from Fort Smith. After a stand off the Indians retreated, having lost 20 of their number.
“The next day an attack came against Fort Kearney. Among the warrior band were the greatest of their warrior chiefs, Red Cloud, Crazy Horse and American Horse. Again the Indians managed to cut off the wood cutting crew outside of the fort…” This is the one in question.
Will ID source of quotes once we get our answers.
PS: Posted the above response before I saw your second post. You are correct Re: the rifles. We'll talk more on them later.