BARNES (COTW6) clocked factory loads with 108-grain slugs at 725 ft/sec for 125 ft/lbs and a 50-yard MRT of 2 inches.
He recommends 3.5 of Bullseye with the 100-grain SPEER PLINKER..... for 1000 ft/sec (which sounds awful hot to me)....... and for 222 ft/lbs ME....
......or 3 Bullseye with a 115 CAST bullet..... for 800 ft/sec and 165 ft/lbs.
Load like that and the gas-seal definitely will be working!
Far as dies are concerned, I use 7.63 Mauser dies for the Tokarev pistol with no trouble at all. Casings are identical, anyway, for Borchardt, Mauser, Tokarev and the Czech monster, the VZ-52, although the LOADS definitely are rising intensity along the list.
Trade-Ex has bulets for the Mauser/Tokarev cartridge and ALSO for the NAGANT. They had Nagant BRASS also, likely will have more soon. Decent prices, too. I was thinking to get some to chop down for my 8mm Lebel Revolver, but then they ran out and we have no Fiocchi dealer out this far in the sticks......so the sticks are stuck, if you want a bad pun.
Hope this helps.
.