Not really. People who were issued bullpups mention how slow they are to reload while prone or in a restricted place. Standing upright is fine but that isn't real world use. And no, I don't know of any bullpup that cuts a whole 10" inches off the length. In general they're about 5" shorter. So that 18" may be equal to around a 12.5-13" traditional rifle. With a 14" rifle our troops have no issues engaging enemies at 400 meters. In general, outside of that range it comes down to other types of weapons.