I am a few years past 70 and have hunted the majority of my life with standard weight rifles, and Leupold and Zeiss , variable scopes, most 3 X 9 and 4 X12. Two years ago my wife bought a Kimber lightweight for me and I promptly mounted a 30mm leupold variable on it. My theory has always been, if you can't pack your rifle, its too heavy or your not in adequate shape for getting the job done. Most hunters stay close to roads, ride on ATV's , and never go far from the beaten path. If you can't pack a 8 1/2 or 9 lb. rifle stay home, you should not be in the woods.
