Bill O’Reilly uses the first amendment as an altar from which to urinate upon the second amendment. Thus he proves that he is a hypocritical pharisee besides being an insufferable asshat.
Most of these bad terrorist use of guns were in Gun free zones. The perps don’t obey laws, guns are easy to get on the black market. Perps frequently get someone else to acquire their guns, so background checks are moot.
In Ft. Hood , Paris, the Orlando club, these gun free zones were responsible for the enormous deadly advantage the terrorist had.
A few people with guns on them for protection could have decrease the carnage, buy killing or wounding the Terrorist before he had time to do what he wanted.
I can only say I can empty a mag of 15 rounds accurately shot to shot in 5 seconds after I draw from my holster.
I think that is typical, many could do so accurately sooner. The Terrorists are the problem not the people with licensed guns for their protection. Its very rare that we use our guns willy nilly. We respect the right to carry and fear using the gun except as a last resort.