A leaked internal memo from the National Institute of Justice–the research, development, and evaluation agency of the U.S. Department of Justice–shows that none of Obama’s gun proposals will work without registration and forced buybacks amounting to confiscation of Americans’ guns.

The memo illustrates this by showing why high capacity magazine bans, gun buybacks, and “assault weapons” bans have failed to work in the past.

For example, according to the memo, the high capacity magazine bans that were in place from 1994-2004 had little impact because the bans contained too many exemptions. The memo says one of the key errors was that “the 1994 ban exempted magazines made before 1994 so that the importation of large capacity magazines manufactured before 1994 continued [throughout] the ban.”

Moreover, the memo points out that while the price of the magazines rose sharply, it was not driven up far enough to make them “unaffordable.”

According to the memo, for a high capacity magazine ban to succeed Obama needs to ban not only the manufacture and sale of said magazines, but also the importation and possession. There also must be a federal buyback of all high capacity magazines already in circulation to ensure private owners haven’t held on to any covered by the ban.

Regarding gun buybacks, the memo says they have also been ineffective “as generally implemented.” Because such buybacks have been voluntary, they have been “too small,” have resulted in the surrender of guns that are rarely used in crime, and have removed guns that are easily replaceable.

The memo intimates that the corrective for such ineffective buybacks are non-voluntary buybacks that are targeted at the kinds of weapons used in crime.

Lastly, the memo says the first “assault weapons” ban failed to work for many of the same reasons magazine bans and gun buybacks failed to work–there was simply too much wiggle room for gun owners. Moreover, the memo says that because “assault weapons” are used in such a low percentage of crimes, the only way a ban can be effective is if it eliminates every “assault weapon” in the country.

According to the memo, the only way to fix it is to couple a ban with “a gun buyback and no exemptions.”