Heres another two using a pepsi bottle to show how big the shell realy is, the bottle is the 1.5litre version so not the biggest one they do but certainly big enough.
A clearer picture than the one before showing just how big these rounds realy are.
Left the green shell is the one from the A-10
Middle is a round from a machine gun
Right is the round from the AK47S and is a standard 7.62
Here that A-10 shell is again note the Hunt for red october DVD Case is the smallest item there, followed by the AK47 magasine and then the round itself.
The pepsi bottle is only around 3 inches taller !