Those are US made Garand M-1 rifles (WWII), and they are heavy weapons (9 POUNDS EACH).plus bayonets
That is about the same as a good old British Army issue Lee Enfield Rifle No 4 Mk1 .303 rifle. I can remember doing (ceremonial) guard duty outside a certain London residence. With fixed bayonet, it certainly was a lot to heft to the shoulder or present arms stance. We didn't have to do it on ice except when the palace grounds were iced over ........ and then the hobnails gave no real grip at all with hilarious results!
They have my admiration.
Colin
