Before I sold my 9mm Nano I reloaded several hundred rounds of ammo with BerryBullets. I always flared my casing and never had any problems seating the bullet and crimping the case. I used the single stage Lee Anniversary press and dies.
I had several Berry's skin the plating off when I first started reloading. I thought it was the bullets.
Next batch of Berry's I noticed the bullets were "slicker" like they had been pre lubed. They did not skin at all.
I since have gone to giving them a little spray of Hornady's bullet lube.
Haven't any problems since that first batch and changed nothing else.
I do NOT flare the cases at all. I only use the full length case sizer from Lee.
I then always use the Lee Factory Crimp die.