If you look at the relative burning rates listed in the Hodgdon No.27 Data Manual H335 is listed as number 55 and H380 is listed as number 72. Number 1 being the fastest and number 97 being the slowest burning. Also, in the same manual it describes the H335 powder as originally being a military powder used in the 5.56 NATO cartridge. The H380 powder was originally used to develop the 22-250 cartridge using 38.0grs. with a 52gr. bullet. Hope this helps!
After today, its all historical