I would also be somewhat leary about what David W. says he can do. Claims he chambers a 30 something or the other that is actually a shortened 308 case and claims he is getting 3000 fps from 150 grain bullets in 16" barrels
I did some looking this AM and couldn't find that claim. I did see that he's working with an improved 308/444/40deg with nearly 30/06 case volume that he calls the 308 Alpo, but I couldn't find any full pressure velocity claims for it. I think he said his forming loads were hitting 2800fps with 155gr.
(edit)
I just found the following velocity claim made by David for the 308 White Express, which is based on the 9.3x74R.
"My 308 WHITE EXPRESS round from 26" barrels, has produced the following velocities from a couple of diffrent barrels...
125 gr. Ballistis Tip - 3,480 fps.
150 gr. Sierra B.T.-S.P. - 3,311 fps.
165 gr. Sierra B.T.-H.P. Game King - 3,262 fps.
180 gr. SPEER Grand Slam - 3,018 fps."
(seems reasonable for a larger than 30/06 case and 26" barrel, but this chamber would seem pointless in a 16")
Mitch