Now you got me thinking I should have gotten a 7.62 AK to SBR instead of my 5.45. I just have a mountain of 5.45 ammo but it seems that the 7.62 would have about 200 ft/# more energy. A loaded mag weighs 1.2 pounds more....which doesn't sound like a lot but an extra 3#s in a backpack all day can...