When loading hard cast lead, always clean excess lube off the projectiles before loading. If your are using projos that consistently are over lubed, you need to find an alternate source of projectiles or you will constantly be cleaning lube off of everything.
About every 5k rounds, I take my die apart and give it a good cleaning. Usually minimal buildup, but I've had some projectiles that were pretty sloppy in the lube department that left a lot of leftover in the die.
On your batch, depending on how you are loading you may need to do some spot checks. Odds are though that if you can feel something different as you are loading, you already know which one(s) need to be pulled and re-seated.