If it's the tumble lube bullet, I know what the OP is talking about, regarding the case mouth seeming to be a long ways away from the bullet.
I cast the .45ACP version of that bullet with wheel weights. I seat it so that the top ring of the bullet is even with the mouth of the case and put a very mild taper crimp on it. That works just fine with all three of my .45s (a Springfield Mil-Spec, Colt Officer's and Llama IX-B.)
I'd try doing that with the 9mm, assuming that it doesn't deviate too far from OAL, and see how it works.
Well we don't rent pigs and I figure it's better to say it right out front because a man that does like to rent pigs is... he's hard to stop - Gus McCrae