I'll jump on the bandwagon and say that you MUST have a scale, and you MUST use it.
I've been reloading for about 15 years. I have NEVER had a reloaded round misfire, I've never double charged or non-charged a case - because I'm very careful. I don't want to spend the rest of my life kicking myself in the rear because I didn't do what I should have, and lost an eye or the use of a hand as a result.
Until a few weeks ago, I used a single-stage press, but now I have the Lee Classic Turret with the Pro Auto Disk. I like the turret a LOT, as it is far faster. The Lee disks are, in my experience, off by one or 2 holes. This is on purpose - Lee would rather you have an undercharge than risk having too much pressure due to an overcharge. Keep in mind that the same type of powder can have different characteristics between batches, despite rigorous quality control. When switching to a new powder (or a new weight of the same powder), I will weigh at least the first 5 charges (dumping the powder back in the measure, of course) to see that I not only get the weight I want, but that the weight is consistent. If I have to go to 10 charges this way, I do it. With the Auto Disk, once I've established that it is doing what I want, I STILL check the weight of the powder every 10-20 rounds. Note: I also check OAL of the loaded rounds - at least every 5 rounds, sometimes more often...as I'm sure you're aware, a round that is too short will have increased pressure, sometimes dangerously so.
Take a bit of extra time and do it the right way. You only have 2 eyes, 10 fingers, etc. - and your fun hobby shouldn't maim you for life. So you'll load a few less rounds per hour (though still a LOT with the turret press) - aren't you worth it?