I tried the 147's loaded with 3.0 of 310 and had problems with the slide not having enough movement to close. I tried the 115 WW factory (Wal Mart) and the gun ran fine. I tried lighter springs & etc, but was advised to stay with the 18 lb spring by XD guru Rich. I now use the 124 MG JHP's with 4.1 of VV 320, OAL of 1.152 and it runs fine. If some of you have problems with the 147 reloads try this one. It works well in my gun.