I don't use tightgroup, but load with power pistol and bullseye. With the power pistol I load to 5.7-5.9 and havehad real good results out of that. With bullseye, its 4.2 grains and also good results also. I prefer the power pistol over the bullseye for 9mm though. I have alot of bullseye fromloading 45, so I am just using it as a backup.