Sometimes softer bullets will help. They seem to get better obturation early on. I have not used cast in any of my 9mm guns yet. I shoot a lot of .38 spcl, .45 auto, .41 Mag. with home cast bullets. All of my bullets are straight wheel weight alloy. BHN on those is guestimated to be somewhere in the area of about 10 or so.
If it is a lube problem then it tends to show lead neat the muzzle. If it is fit it starts closer to the chamber, and tends to follow the rifling.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.