Every reloading manual shows bullet diameter of .308. Reloaded 200 rounds with two different mfg 110 grain bullets. One batch shows bullet diameters between .308 to .309. The second batch all measured at around .305. Both bullets were listed and sold as .308 for M1 Carbine. After finding this variance I checked two commercial 30 carbine ammo. Both Armscor and Remington measured .305. If it is suppose to be .308 why variance. Concerned the ammo I reloaded that measured .308 may be oversized and not safe to fire. Inputs please thanks.
Wow .305 is small. It should be no smaller then .307 which Remington almost always is and .309 that others use. I would guess that the pressure of the burning powder is supposed to force the bullet to expand to fill the barrel but to increase 3 thousands is quite a bit and more if your bore is a bit worn. If your bullets are at .308 then your fine so enjoy shooting them.