M14 Shooter
The Light of Truth
If by "other calibers" you refer to "other" .224" rounds, like .222 Remington and .22LR, then sure.The only thing I would argue with is the claim that the AR-15 is not a high powered rifle. While the round it fires is undersized, compared to many other calibers, it is certainly high powered.
Compare 5.56 to the small.243" or .234" magnum rounds - you will see it is not 'high powered'.