First off, the below data/PF was gathered using a G-34. This information is critical IMO when discussing PF. For example, same load in my 34 has a substantial different PF than out of my PCC due to the longer barrel.
I use a Lee load master.
4.5g CFE, 124 BBI= 134 Avg PF
4.2g CFE, 124 BBI= 128 Ave PF
3.9g CFE, 124 BBI= U/K (Need to Chrono but noticeably softer shooting) Shot close to 600 in a level 2 state match sat and sun and not one issue. This is my load I like the most and if it makes PF for USPSA matches I will use it. However, I still want to lower the PF for steel challenge matches and loaded 50, 3.9g CFE, 147 X-treme last night. Need to chrono but I am looking for it to be about 125-126 PF at 860 FPS.