Standard factory loads for the .308 with 150 gr. bullets is 2820 fps out of factory test barrels. Most of these barrels are 24" long as a standard. With a 22" barrel you are right were you should be. I've been reloading a long time and I understand what the books say and you can achieve a little more velocity with the 308. If you were to gain say 70 fps to 2820 fps you would never be able to tell the difference in energy levels or bullet drop. It seems your load works and that you shoot it very well, so don't mess with a good thing just keep droppin in there tracks. Good luck and Good Hunting!!!!