Oh boy, does this letter writer need some educating...
LETHALITY (not appearance) is the real gun issue. Semi-automatic and automatic weapons are military and police tools. They were designed to kill the enemy as quickly and efficiently as possible. Any distinction is academic between Semi- and Automatic weaponry. "Conversion kits," readily available on the grey-market, easily can reconfigure a semi- into an automatic weapon.
Definitions: A SEMI-automatic weapon automatically ejects the spent cartridge and automatically rechambers the next bullet. But you must pull the trigger for each shot. A fully AUTOMATIC weapon (ex: AK-47, Browning M2E2, UZI, HK-417) does all of the above, plus it will keep firing as long as you pull and hold the trigger, until the magazine is exhausted. (By the way, only Automatics are true "assault weapons." I wish our legislators would get their terminology straight. They leave a loophole large enough for the NRA's Wayne LaPierre to slither through!)
Neither style weapon — nor its accoutrements (30 > 50-round magazines, 100-round drums, unjacketed or hollow-point bullets, stockpiled ammunition -- have any business in the hands of civilians. (If one wants to outfit themselves with such an arsenal, I suggest they join a WELL-REGULATED Militia — as detailed in the 2nd Amendment of our Constitution)...the Marine Corps, the Army infantry, the Seals, Delta Force, the Virginia National Guard, or any big-city police SWAT team.)