Sellier and Bellot offers a 7.62x39 123gr SP with a claimed MV of over 2400fps. This stuff is cheap and normally fairly good quality ammo. They use the correct .311 bullets also.
http://www.sellierbellot.us/index.php/products/view-product?id=204
Looks like it works too
Last edited by Gm54-120; 10-13-2018 at 07:51 AM.