Oh dear. This video purports so much ignorance. For a start the British used the .44 calibre Adams pistol in the Crimean War and the Indian Mutiny both of which occurred before the US Civil War and US gun manufacturers were familiar with the Adams a copy albeit in .36 calibre being produced stateside ergo it was understood that the Henry rimfire cartridge was a pistol level round at the time it was introduced. Wagon Box Fight funnily enough rather 300+ it would seem that rather than the account from the other side is more like the Sioux and Cheyenne lost between 6 and 50, also Springfields did most of the work. Oh and yep Little Big Horn...really we are heading into enough said territory. In fact erm yes he says absolutely nothing about it, some Garry Owen and we are supposed to be sold here? Oh we have a return to the battle later with a discourse on the archaeology and then some surmise on the usage of Henry/Winchester's there but no actual evidence.
Allatoona fortifications may have had something to do with the Union holding, Wagon Box...well there is the wagon box and no mention in the InRange account of the relief force bringing along a howitzer along with a wild exaggeration of the Cheyenne and Sioux casualties (seriously 300+ dead would have broken them forever, these were small populations), Little Big Horn is a litany of division of force, poor coordination between the widely separated detachments and...well then there is an awful lot we will never know about the battle but Custer who had in fact been a very impressive soldier in the Civil War and certainly managed to be combat savvy long afterwards had a really off day and he and a lot of his men paid the price.
What I am not seeing are any accounts of the US Army being outgunned in fights with the Native Americans, any examples you may have would be welcome because my suspicion here is that the InRange channel has sold you a bill of goods with a very selective where not downright inaccurate reading of history. We know from numerous wars that field fortifications could prove an impediment to regular armies let alone the forces of native peoples, the British after all held Rorke's Drift just fine with their single shot Henry-Martinis. Thus rather than a single example of a front being held by fire, which would I admit make a much more effective argument, we have two examples of victories from behind cover and one of a balls up without it.
To make their argument they really do need an argument of a force US military, US civilian or Native American or even other does not matter which holding its ground by dint of the firepower of Henry Winchester type rifles alone. I am not cross with you piratedude, you have taken the evidence that InRange have presented on trust. I am angry with them for so blatant a manipulative presentation which ignores known facts and distorts several incidents without offering the viewer a chance to consider all the factors for themselves and assign a weighting in their own mind.