The following are excerpts from the testimony of David Hardy, a scholar who has written extensively on gun control legislation. The entire testimony is contained in an PDF file here.
What is an "Assault Rifle?
“Assault Rifles” The very term “semiautomatic assault rifle” is internally contradictory. In World War II, rifles of standard military power could not be made full automatic, because the recoil (“kick”) was too powerful. The “assault rifle” concept involved cutting the cartridge’s power, and thus its recoil, in half, so that it could be controlled in full automatic fire. An assault rifle redesigned to be semiautomatic is simply a semiautomatic firing cartridges with half the traditional military power.
In Common Use
Heller v. District of Columbia noted that “Miller said, as we have explained, that the sorts of weapons protected were those ‘in common use at the time.’” 128 S.Ct. at 2817. I have elsewhere noted my difficulties with this test,3 but it is clear that the AR-15 platform has become the epitome of a firearm “in common use.”
Based on these data, it is clear that the AR-15 platform qualifies as a firearm “in common use.” The same would be true of the AR-15’s standard magazines, which hold 20 or 30 rounds. The number of these in use (many of them sold as surplus by the government itself) is certainly in the tens, and perhaps in the hundreds, of millions.
Insurmountable legal issues
These legal problem could be solved in one of two ways, either of which, I submit, is constitutionally unacceptable, or practically impossible. Congress could, in addition to the private sales ban, either 1) Impose national firearm registration, covering all firearms in private possession,10 or
2) It could make all firearm possession illegal, period, providing for a defense if the gun owner can prove they bought the gun before the effective date of the ban, or bought it from a licensed dealer after the ban.
Then anyone who possesses a firearm could be arrested and indicted on that possession alone, and be made bear the burden of proving the legality of their acquisition of of the firearm at trial.
Absent (1) or (2), a private sales ban could not be enforced. (1) would require greater precision than appears possible at this time,11 and
(2) would be, I submit, clearly unconstitutional, since it treats exercise of a constitutional right as presumptively a crime.
What does prevent mass killings is a defender, out of uniform and thus not known to the killer, who can deliver immediate and accurate counter-fire. Thus:
• In San Antonio, an off-duty officer shot the attacker down, and limited
losses to two persons wounded.13 • In the New Destiny Center shooting in Aurora, Colorado, the gunman was
brought down by Jeanne Assam, a church-goer with a concealed weapons permit; the death toll was two.14
• The shooting at Pearl High School in 1997 ended when the vice-principal drew a .45 and confronted the shooter. The death toll was three.
I highly recommend reading the entire testimony.