I will admit my customers get a bit more out of my 7mm AM then I do simply because I do not load mine all that hot.
Still, The way I load mine, it will do a solid 200 fps more then the 7mm RUM with bullets over 160 grains.
With lighter bullets, the advantage will drop to around 150 fps.
For comparision numbers, this is what my personal 7mm AMs will do with relatively comfortable load levels:
Lightweight 7mm AM, 27" Lilja 1-9, 6 groove barrel:
140 gr Accubond...............3570 fps
160 gr Accubond...............3490 fps
175 gr SMK......................3380 fps
200 gr ULD RBBT...............3200 fps
Heavy 7mm AM, 30" Rock 1-8.7, thin 5R barrel
160 gr Accubond...............3560 fps
200 gr ULD RBBT...............3340 fps
These are top end velocities. My go to load in my light 7mm AM drives the 200 gr ULD RBBT to 3150 fps. In my heavy rifle, its preferred load is the 200 gr ULD RBBT at 3270 fps so just a bit off max in both.
Hope this helps some.
Please realize that there is case forming involved with the 7mm AM and fireforming. I am setting up to offer formed cases for customers in this chambering and should have that up and running this winter so soon that will not be a problem for customers. I can supply the cases or you can send me your virgin 338 Lapua cases to be formed at a cost.
Kirby Allen(50)