Hornady, Speer, and Privi all sell 123gr .310" bullets made for 7.62X39. The Hornady manual has load giving velocities up to 3100 FPS.
Anyone ever tried these through a Mosin Nagant? I was thinking of taking my PU Sniper coyote hunting. I think a 123 VMAX at ~3000 fps would be bad medicine for varmints.
Can't say I've done that, but I swage 5.7x28 brass into a nice little 125-ish grain pill an the same lines as a Glazer that is pushing just shy of 3200fps through the Mosin. I'd have to go out to the shop to get load and powder data for it, but it's a scary little pill on anything soft.
And THIS is what remains after scattering a wet-pack all over the yard...
And this is what was previously packed tight with soggy newsprint... I didn't empty it--the bullet did--in a 15M radius of soggy pulp making many plopping sounds for several seconds after the shot.