Let's think about this; you want to run several *miles* and then shoot and you are worried about how fast you can get to the ready? I'm with 9mmepiphany in that you should take a page out of the biathlon playbook: two-shoulder harness sling. Yes, you won't be at the ready as fast, but if accuracy counts for anything when you get to the shooting, you will need the time to slow your breathing anyway.
Cross-country skiing is something like 3x harder than running I've heard. These guys ski for miles and then shoot a fairly small target off-hand or prone. If you watch them, they are not in that much of a hurry transitioning from ski to shoot; they are quick and smooth, but they are also taking their time. They don't ski with a round loaded and I don't see the point of running with a live round in the chamber; how long does it take to rack? My point is that if this is a competition, your time will be made up either running, or shooting, but not in the transition.
I agree with others that if you are in a tactical scenario with short distances involved, either keep it in the strong hand, or add the weak hand to the magwell, muzzle down if possible.
Cross-country skiing is something like 3x harder than running I've heard. These guys ski for miles and then shoot a fairly small target off-hand or prone. If you watch them, they are not in that much of a hurry transitioning from ski to shoot; they are quick and smooth, but they are also taking their time. They don't ski with a round loaded and I don't see the point of running with a live round in the chamber; how long does it take to rack? My point is that if this is a competition, your time will be made up either running, or shooting, but not in the transition.
I agree with others that if you are in a tactical scenario with short distances involved, either keep it in the strong hand, or add the weak hand to the magwell, muzzle down if possible.