It sounds like you set the rifle up nicely, but it certainly is not a light weight. I think that's a good weight for a rifle intended for 1K, but then I would want a more potent cartridge. I've had two .300 WSM
's and now this .270. I've been happy with the performance of these rounds. Being a 7mm fan I would have had mine chambered that way had I commissioned the rifle. I bought it NIB from someone else who made me a deal I was not going to let pass.
My rifle, at a good 2 lbs lighter than yours, still has enough heft to settle right in for 500+ yard shots on marmots, but is light enough to make a good backpacking rifle.
The Stiller Predator action has a long enough magazine I believe you could chamber for a seating depth similar to what you currently have.