You could push them harder, but that is the velocity I am getting....but then again once I had the gun rebuilt I have fired it less than 40 times, and I blew the first one up with 17 rounds down range. I was going for accuracy more so than for velocity.
I really do not think there is anything you can do with the 7/338 that you could not do with the 7RUM unless you want to run upper end loads. The lapua brass does make that a little more obtainable with case life. I do however think that the lapua case lends itself to being improved, more than the RUM case. One day this project will get back on my mind and I will order and improved reamer and run improve mine. Till then I will keep shooting the light but very accurate load I am using right now.
I can't recall whether it is 95gr of wc872 or 95gr of 870 but it shoots well enough that I am not too interested in tweking it.