They'll never make a dent in the number of guns no matter what laws they pass or how they enforce them. Estimates say there are between 300 million and 500 million guns in private hands with several million more added ever single year (the vast majority not registered and with no way for the government to track ownership). Guns are durable goods and rarely break or need repairs (which is why there are still plenty of guns from the early 19th century for sale). So there is a high likelihood that vast majority of hundreds of millions of guns are still out there and in perfect working order.
They'll never make a dent in the number of guns no matter what laws they pass or how they enforce them. They'll never make any dent in the number of ILLEGAL guns, just those owned by legal owners. THOSE are the people those in the government are really afraid of.
The illegal gun owners, i.e. criminals, are just to be used as a club against the legal owners.
Mark