7.62X39 has lots of power. Modern bullets were always the issue. .311 is not common.
But your source of information is wrong. Your graph says 583lbs with the .357??? Yea, I got 1320lbs with BB loads, and 900lbs with more common from a 16". And that chrono verified by me.
They can be off, but being wrong by a factor of 2 to 1? Not addressed to the OP, but whoever made the graph: If you need to lie to support your idea, ask yourself why you believe it?
But your source of information is wrong. Your graph says 583lbs with the .357??? Yea, I got 1320lbs with BB loads, and 900lbs with more common from a 16". And that chrono verified by me.
They can be off, but being wrong by a factor of 2 to 1? Not addressed to the OP, but whoever made the graph: If you need to lie to support your idea, ask yourself why you believe it?