Ken,
I would wager a drink those two known serial#s belong to my friend and they are 22" barrels. Want me to call him again and find out. We could meet at Pidcoke! I think if there is a 24" medium weight M77 ST in 7x57, it is worth too much to hunt with.
Lee
The is a 77ST 7X57 with a 24 inch barrel. I handled one in the 80's
Doc
