It's the size of the bullets

For people who aren't aware, this is why I laugh at how huge the rounds for the Russian M44 rifle are. On the right are two 5.56mm (.223 Remington) rounds. These are the bullets that the US military uses in the M-16, the M-4, and the SAW. (For those of you not gun literate, this means these bullets are used in most US military rifle and machine-guns.)

On the left is the 7.62x54R round used in the M44.

Now you see why I had a bruise on my shoulder after firing the M44 at the range.