Hodgdon uses 24" barrel data. Same with Lyman as well. I also believe that Nosler uses 24" barrel data. There are many 308 loadings using the 200 gr bullets with velocity listings in the 2400s along with one or two in the low 2500 fps range.
Depending on the bore, individual rifle and powder choice, the 308 is very capable of 2500 fps with 200 gr bullets out of a 24" barrel.
