Here is something I posted over at Castboolits...
I have been working on a gas seal load that would replicate the velocity of a Military Surplus Nagant 7.62x38r round for a couple of months and thought I'd share what I found.
Boolit: Lyman 311008 FN 115GR
Case: PPU 7.62mm Nagant
Powder: Trailboss 5.1gr C
Primer: CCI 550
Dies: Lee M1 Carbine (with custom seating), Lee Universal Decapping, Lee Universal Expander (with custom flare die), custom crimp die.
Data: (taken from 10ft from the muzzel)
Test Round: 113 GR Cast Boolit Gas Seal
Hi Vel: 974
Low Vel: 834
Ave Vel: 907
Ext Spread: 140
Std Dev: 36
Basline: 108 GR Military Surplus Gas Seal Round
Hi Vel: 937
Low Vel: 846
Ave Vel: 900
Ext Spread: 91
Std Dev: 30
Let me know if you have any questions, if this is useful for you and if you have any feedback.
Here are the dies in order of operation...
decapper, expander, <prepared case>, M1 seating die, custom crimper, M1 sizing die.
Here are three finished rounds and a cast boolit...