For me it definitely would be a .22. A combo of some semi auto rifle 10/22 or 795 and a hand gun.
I have small pouch, maybe the size of a large grapefruit or 1 1/2 times the size of a soft ball or there abouts. It currently holds 12 magazines for my P22, 12 for the 795 and 6 magazines in 17HMR for my Savage 93. Fully loaded you can lift it up just with your pinky. You can pick up a box of 5,000 rounds of .22 with one arm. A 795, the P22 and all the loaded spare magazines are lighter than most rifles mentioned here empty.
I have small pouch, maybe the size of a large grapefruit or 1 1/2 times the size of a soft ball or there abouts. It currently holds 12 magazines for my P22, 12 for the 795 and 6 magazines in 17HMR for my Savage 93. Fully loaded you can lift it up just with your pinky. You can pick up a box of 5,000 rounds of .22 with one arm. A 795, the P22 and all the loaded spare magazines are lighter than most rifles mentioned here empty.