There is a very valid reason for this, Mr. Shea:
"the gun industry refers to them as "modern sporting rifles" rather than assault rifles"
The rifles being discussed are not 'assault rifles'. By definition, an 'assault rifle' must be chambered in a moderate caliber such as 5.56X45.. or 7.62X39mm AND have select-fire capability.
Such select-fire capable rifles are tightly regulated under the National Firearms Act of 1935 and each one requires registration with BATF as well as payment of a $200 transfer tax and extensive background check on the owner.May 4, 2012