I want to make some decent deer hunting ammo by substituting either Sierra Game King 125gr or 150gr .311 soft points into Russian 122-125gr or 154gr+/- steel case ammo as appropriate.

I just plan to pull the bimetal bullets and substitute the Sierra’s. Poor accuracy is often due to poor bullet consistency regardless of powder charge or velocity consistency. What Russian steel case shows the most consistent velocity regardless of good or bad accuracy?