Felons, illegal immigrants and all others banned from buying a gun in the United States have a new alternative if they’re looking to get their hands on a firearm: Just buy a toy.
In my lifetime I have known as friends, neighbors or relatives bootleggers, dope dealers, prostitutes, fence, burglar, members of a motorcylce club, city patrolmen, city detectives, corrections officers, ex-county sheriff, both sides of the law have talked to me about crime and guns for half-a-century.
Before I was 18 I possessed a .32 Walther PP (war trophy), a .32 Iver Johnson (sold by a NYC gambler for gas money at a TN/VA stateline bar), and a .22 derringer (used, private owner) from a thriving gray market (late 1950s and early 1960s there was a lot of talk of banning handguns, check the Eisenhower Commission). Plus guys in shop at school bragged about making .22 revolvers out of blank guns.
Wright and Rossi wrote up the NIJ felon survey (aldine 1986) that cited criminal sources for guns as dealers in contraband, theft, burglars and fences, burglary by the felon, gift or purchase from friends or relatives, used guns from private parties, and seldomn legally regulated sales. In Marvin Wolfgang "Patterns in Criminal Homicide" study the guns used in shooting homicides were mostly street sales.
A criminal could spend $350 on a metal airsoft rifle, do some gunsmithing, add a $500-$750 upper and have a new alternative if they’re looking to get their hands on a firearm. Alternative to what? For ~$1000 there are a lot of stolen military and police full-auto, unpapered war trophies, underground manufactured gun (what was CSAL raided for in Arkansas for instance), and smuggled illegal full-auto coming in with the illegal drugs: those guns have been used to kill people. Getting all worked up over a convertible toy seems like a displaced concern to me, especially since the questioned airsoft guns were not recovered from violent crime, but the concern appears to be just "what if" or "someone could" speculation.
The idea that criminals legally buy guns from legal sources does not jibe with my experience. In a similar vein, illegal sex is a problem: let's pile restrictions on marriage licenses until we cure it.
The problem with gun crime is criminal behavior, most of whic is already against the law.