I use the Lee FCD for 357sig and is very happy with it. I have loaded over 4K loads, with no setback.
A while ago I created some 357sig loads using the Lee FCD and also chamfered brass with no crimping. I did not see any difference in the setback test I did. I created 5 loads using the chamfer method, and 5 matching loads using the Lee FCD. My test results showed that 4 out of 5 Lee FCD loads grouped better.Today I am still using the Lee FCD. Following are the loads I tested:
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: 0.378"
RMR, 147gr, TCFPMW, CFEpistol, 5.7gr, CCI500
Average: 1006
ES: 17
SD: 6.8
Force: 330
PF: 147
Velocities: 996, 1013, 1006, 1012, 1007
Grouping @ 15yd: 0.72"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: chamfer
RMR, 147gr, TCFPMW, CFEpistol, 5.7gr, CCI500
Average: 1000
ES: 63
SD: 26.4
Force: 326
PF: 147
Velocities: 954, 1008, 1013, 1017, 1012
Grouping @ 15yd: 1.44"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: 0.378"
RMR, 147gr, TCFPMW, CFEpistol, 5.9gr, CCI500
Average: 1038
ES: 30
SD: 12.3
Force: 352
PF: 152
Velocities: 1033, 1046, 1031, 1056, 1026
Grouping @ 15yd: 1.04"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: chamfer
RMR, 147gr, TCFPMW, CFEpistol, 5.9gr, CCI500
Average: 1043
ES: 18
SD: 7.6
Force: 355
PF: 153
Velocities: 1048, 1031, 1047, 1049, 1040
Grouping @ 15yd: 1.4"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: 0.378"
RMR, 147gr, TCFPMW, CFEpistol, 6gr, CCI500
Average: 1064
ES: 19
SD: 7.4
Force: 369
PF: 156
Velocities: 1065, 1057, 1059, 1076, 1064
Grouping @ 15yd: 0.5"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: chamfer
RMR, 147gr, TCFPMW, CFEpistol, 6gr, CCI500
Average: 1063
ES: 11
SD: 4.8
Force: 369
PF: 156
Velocities: 1069, 1064, 1058, 1059, 1067
Grouping @ 15yd: 0.78"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: 0.378"
RMR, 147gr, TCFPMW, CFEpistol, 6.1gr, CCI500
Average: 1071
ES: 12
SD: 4.8
Force: 374
PF: 157
Velocities: 1073, 1069, 1065, 1075, 1077
Grouping @ 15yd: 1.39"
Test Date: 11/20/2018
357sig, P229, 3.9"
Case: Speer
COL: 1.140"
Crimp: chamfer
RMR, 147gr, TCFPMW, CFEpistol, 6.1gr, CCI500
Average: 1071
ES: 13
SD: 5
Force: 374
PF: 157
Velocities: 1072, 1063, 1071, 1074, 1076
Grouping @ 15yd: 1.13"
Test Date: 11/20/2018
I load the RMR 124gr Match winner all the time in 357sig. The COL I use is 1.140". The test I use the make sure the ogive is not inside the neck is to use a resized case and place the mouth over a complete round. If the ogive is inside the neck then the resized case mouth will touch the mouth of the completed round and turn easily. If not, then it will rest on the ogive and will not turn easily.
Good luck with loading 357sig, and be safe.