I just realized that they go out of their way in a few scenes to point out how powerful the hawken rifle is, showing Jeremiah get knocked on his back firing it at buffalo and so on.
But when he goes to attack the crow war party he actually fires it one handed (and the other rifle in his other hand) Maybe his rage gave him super strength.
Jeremiah Johnson is not knocked on his back firing at buffalo because of the rifle but by neck swinging of his horse who is frightened by the shot fired so near to its ears, I suppose.
He had rage alright, rage at the horror of what two people had gone through, two people he'd learned to love in spite of himself -
And rage reawakened by that nightmare.
Don't forget, in the start of the movie we see him exiting the world as fast and far as he possibly can and he is wearing a military uniform. Whatever caused him to set his mind on that determined exit from all he knew below couldn't be pleasent.
Then, instead of finding himself in blissful isolation he learns to care for these other two unfortunate souls, and love begins.
Remember how he shaved for his bride when he realized his beard hurt her?
Well, that came to an abrupt end full of new agonies and regrets figuring he failed the boy and his bride. What nightmare of imaginings he's left with over what they endured -
Caleb's worst fears realized just for starters...
That child was so traumatized the first time he watched helpless as his family was slaughtered he actually lost the ability to speak, and then it happened again only this time there was no escaping the inevitable.
And he was so close to speaking again, did you notice?
Jeremiah was now doomed to relive these thoughts for the rest of his life, thank-you very much (insert Indian tribe), and for what?
Being sucked into the service of helping others once again, same as wearing the uniform. Take off the uniform, wear the uniform, did it matter?
New rage on top of a reborn ancient rage on top of outright outrage!!!
Can you see how this moved him far, far beyond fear?
He wasn't strengthened by muscle power, he was strenghtened by zero fear which enabled him -
He could calculate and deliberate and move with an enraged will compelled to bring about a reckoning.
This is not the sort of guy you would want to kid around with thinking you might ease his suffering with tidbits of small talk.
Jeremiah Johnson was on a mission, and what we see is a deliberate calm.
Did you know that Doc Holiday was described as having that same deliberate calm under fire and that is what some say made him so deadly?
Look where no one else is looking and see what no one else sees.
First off, a fifty cal. hawken does not have a recoil so strong it would knock you down. ( unless you were already severely off balance) I know cause I own one. As to firing it one handed, that kinda makes sense as the recoil would be felt more with the rifle held against your body ( shoulder) then if it was allowed to recoil in your hand.
As with any other black powder firearm (I've owned & fired several, myself), it all depends on how much powder you load. A lot of powder, a lot of kick; less powder, less kick. For those handheld shots, he might have loaded lightly, for small game; the recoil might well have been minimal, coming out of heavy long-guns.