I am actually currently working on a load in my 7mm-08 using 139gr. GMX's and RL-19. Right now I am at a pretty hot load, 49.5gr. This load works quite well and is very accurate.
For some reason, The GMX bullets I've played with shot much better below max. The faster I pushed them, the worse they shot. About 75 to 100 fps lower than max pressure speeds was the sweet spot.
I'm running 42.5gr of Varget, Win case, CCI 200 primers with the 139 GMX. All precautions apply. This load is safe in my rifle. It does an awesome job on deer.