Custer was outgunned as far as repeating arms go. The Calvary was equipped with .45 Colt 1873 revolvers and 1873 Springfield 45-70 carbines. Both good weapons, but the Indians were thought to have quite a few repeating rifles such as Henrys, Spencers, and Winchesters.
Kind of funny really.
Winchester used the slogan "The gun that won the West", but since the army was using Trapdoor Springfield's it was actually the gun that LOST the West .
While it is true that a large portion of the civilian population owned and used Winchester's, they were focused on self defense and not militarily significant.
He was up against a force protecting their own back yard! The Lakota, Cheyenne and other tribes used the same tactics didn't they? ........................snip.........................................
Not arguing, just curios because I can't stand non-fiction...reminds me of reading GE specifications... 
You just aren't reading the right authors .

There is also a lot of very accurate "Historical fiction" that may have a fictional story with an incredibly accurate background.
One example that leaps to mind is the Shaara series of 4 books
1 "Gone for Soldiers" covers the Mexican war introducing young men like Capt R. L.Lee , Lt Thomas Jackson, and Lt. U.S. "SamGrant,
2"Gods and Generals" covers the period up till June 30th 1863
3 " The Killer Angel's" is about the battle of Gettysburg
4 "The Last Full Measure" covers the rest of the war .
But to answer your question, yes, the plains Indians, Lakota, Cheyenne, and Kiowa were considered by many international military experts to be the finest light Calvary in the world.