Home Forums Hunting & Shooting Hunting Rifles What does 223AI mean?

My grandfather smoked like a chimney for 60 years, and drank like a fish until last year, and he is still alive and kicking, living by himself even. He is 91. My other Grandfather is still spry at 87, and he drank like a fish his whole life. Methinks there be some good genes in my family for living to excess in every way, including longevity.