It says "the right of the people to keep and bear Arms shall not be infringed." Where does this imply that there is a restriction on what arms people can keep and bear?
The preamble of the amendment is: "A well regulated Militia, being necessary to the security of a free State." The amendment can be interpreted so that only those arms "necessary to the security of a free State" are protected.
Also, note the First Amendment says that Congress may make no law abrdidging the freedom of speech. This does not imply that one can say whatever one pleases. One cannot commit perjury, publish libels, or threaten to kill someone. The First Amendment cannot be interpreted in an absolutist fashion; the same applies to the Second Amendment.