Describe load, results you are getting & slug bore
There is a lot of variation in 9mm Parabellum chambers, throats and barrels. Some barrels are not supposed to be compatible with cast bullets (eg polygonal rifled). The 9mm is less forgiving than lower pressure cartridges.
As with any other barrel, I use a bullet at least as large as the groove diameter, and preferably .001 or .002" larger. If your chamber will not allow a cartridge with a large enough bullet to chamber, don't use cast bullets in that barrel. Use of too small a bullet will give you incredible Leading. I use a .356" or .357" lube die for 9mm.
The 9mm is not demanding as to lubricant. I've always preferred 50% Alox/50% Beeswax.
I've used two truncated cone bullets of about that weight over the years. The first was the Lyman design, and I used Unique powder with it. If I measured bullet weights so they were consistent, and weighed every charge of Unique, results were excellent.
Of late, I've also been using a shorter commercially cast truncated cone bullet from Meister. I'd rather cast my own, but I was offered them for $29 per thousand, delivered, by Brassmanbrass, which is about the value of the Lead. I've been loading them with a moderate charge of 231.
CDD