YankeeTarheel wrote: Mon Mar 19, 2018 4:11 pm... I expect a 30-30, a 30-06, and a .308 are all far more lethal than a .223 as well.
I was at the range recently with a friend who has an AR10 -- I had my chronograph with me because I was testing some handloads for my socially permissible wood-stocked bolt-action hinged-floorplate-magazine hunting rifle -- anyway, stuck it on his rifle just out of curiosity -- 2825 FPS with a 150 gr bullet.
Looking at some basic numbers in my Hornaday reloading book, a 55 gr. bullet hitting 3250 fps at the muzzle, has 1290 ft-lbs at the muzzle, 992 ft-lbs at 100yds, and 413 ft-lbs at 400 yds, 298 at 500 yds. The 150 grain .308 with the worst BC for an FMJ (I don't have any numbers for the Russian bullet his ammo used, but it was FMJ so I just picked the bullet in the book with the lowest BC), has 2658 ft-lbs at the muzzle (using the measured 2825 FPS muzzle velocity), 2246 ft-lbs at 100 yds, and 1302 ft-lbs at 400 yds, 1070 at 500 yds. Bullet drop is comparable (the .308 drops 30.7" at 400 yds and the 223 drops 27.4"; at 500 yds it is .308: 56.9" and .223: 53.9"). I know raw energy numbers aren't the whole story, but that .308 packs some real punch.
For 30-06, the same bullet I based my assumptions on for the .308, my book shows a max velocity of 3000 FPS which works out to be about 340 extra foot pounds at the muzzle over the .308, and 200 ft-lbs extra at 500 yds.
For 30-30, a 150 gr roundnose with a BC of 0.186, book shows max velocity of 2300 FPS. The 30-30 still beats the .223 on energy (1762 ft=lbs at muzzle, 311 ft-lbs at 500 yds) but the .223 kicks some 30-30 butt on bullet drop -- the 30-30 drops 75.5" at 400 yds and 149.7" at 500yds. At 300 yds, the 30-30's 31.1" drop is basically the same as what a .223 or .308 drops at 400 yds.
Sorry -- probably dull -- but it was fun for me.