RC20 is well intentioned but wrong in his assertion of complete safety in starting in the middle of a load range. It depends on the powder and other components involved in the recommended range. I've twice in my life encountered loads at the bottom end of a recommended range that turned out to hard maximums for the guns I was using them in.
You don't need a lot of effort to work up. A general recommendation is 2% steps. So if a load range starts at the usual 10% below maximum, you have only 6 rounds to go to maximum, while looking for overt pressure signs. It's not worth not doing it, just in case you've got one of those peculiar combinations in hand.
Thank you for the compliment, but I too would like to know what the circumstances are.
Frankly I have never sue the lowest levels. Depending on the gun its mid range, sometimes between low and mid, but never the low.
If there was an exception it would be an old gun of uncertain capability but I do not shoot those.