Originally Posted by RustyGrill
Really it shots both ??? With conversion or just stock
Not sure here, because I'm a pistol man, but it sounds like one of those 38sp/357mag things, where same gun, conversionless, can shoot both rounds because they're technically the same size/caliber just different performance levels. Or something like that. Do a Google search I'm sure it will turn up something on it. I'll try and do a little research on it as well...
So it seems as tho the 223 I'd slightly smaller in diameter but Chambers in ARs chambered for 5.56"... I'm sure someone more knowledgeable in rifles can help elucidate.