Within my measuring equipment, I can't determine a significant difference between WLP or WSP in a 45 ACP case.
Rock Island Arsenal GI M1911 RIA 5" barrel
230 FMJ 7.8 grs AA#5 Lot DM WLP OAL 1.265" taper crimp 0.469"
13-Sep-18 T = 82 °F
Ave Vel = 815.4 fps
Std Dev = 18.02
ES = 68.22
High = = 847.6
Low = 779.4
Number rounds= 28
230 RMR FMJ 7.8 grs AA#5 Lot DM small primer brass WSP OAL 1.265"
taper crimp 0.469"
10-Jun-20 T = 91 °F
Ave Vel = 805.6 fps
Std Dev = 12.56
ES = 39.38
High = = 822.4
Low = 783
N = 16
Powder charge differences create more velocity variances than does the primer.
Rock Island Arsenal GI M1911 RIA 5" barrel
230 FMJ 7.8 grs AA#5 Lot DM WLP OAL 1.265" taper crimp 0.469"
13-Sep-18 T = 82 °F
Ave Vel = 815.4 fps
Std Dev = 18.02
ES = 68.22
High = = 847.6
Low = 779.4
Number rounds= 28
230 RMR FMJ 7.8 grs AA#5 Lot DM small primer brass WSP OAL 1.265"
taper crimp 0.469"
10-Jun-20 T = 91 °F
Ave Vel = 805.6 fps
Std Dev = 12.56
ES = 39.38
High = = 822.4
Low = 783
N = 16
Powder charge differences create more velocity variances than does the primer.