I have had two 7.62x39 bolt rifles, a Century Mauser conversion, and a Savage 10FCM Scout. The Mauser was simply a bad choice. But the Savage is one of my favorite rifles for walkabout shooting.
I removed the Scout mount right off the bat, not a Scout kinda guy am I. The bore is 308 diameter, and it's shoots surprisingly nicely with 110gr V-Max handloads. The scope is a Cheaper Tasco 2.5-10x42 MilDot on a conventional EGW Steel 20MOA base.
This is an older and discontinued Savage model with a 4rd D/M.
It may still be available from the aftermarket.
I also own Mossberg MVP .223, which likes nearly every AR magazine I've tried (some of the plastic ones are a bit tight). No Oryx yet, but they are showing it as a possible option on
a signup request sheet.
With the Bushnell AR Drop Zone 223 BDC scope, it's bang-on at 100, 200, and 300yd distances on a 100yd zero, has aim points for 400yd, 500yd, and the top of the lower reticle wire can be used where it gets thick for 600yd. It's BDC is configured to match 55gr-62gr Ballistic curves. It's a heckuva combination with Fed Fusion MSR 223 62gr.
If I were a Prepper, this one would be my goto rifle.
What I will suggest to you is a Ruger American Rifle chambered for 6.5 Grendel. It accepts AR style magazines, and 10 rounders can be obtained from Midway. I'm guessing, but I think they'd work. I'll probably find that out myself, since I just bought a 6.5G 20" Upper.
It looks like there may also be an Oryx chassis for this action, too.
I'm looking at the
Ruger American Rifle Predator 22" 6.5 Grendel for something like what you're describing.
The 6.5 Grendel will fit the cartridge profile you're looking at, and will outperform either the .223 or the 7.62x39. Factory loads are available ranging from
90gr American Eagle Varmint/Predator, to
Federal Fusion MSR 120gr PSP Deer Loads.
Greg