The Second Amendment reads. "A well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed." The question may be asked, "Is registration of a particular gun truly such a burden that it can be called an infringement of the right to keep and bear arms?"
To begin with, if we were speaking of registering religious items or communications devices, none but socialists would dare ask such a question. Yet the Second Amendment directly follows the amendment concerned with the free exercise of religion and freedom of the press. The Second Amendment holds a place of priority in the Bill of Rights, which is primarily a list of inalienable personal rights.
But to answer the above question — Yes. Registration is absolutely an infringement, on at least three grounds. In fact, we will see that the rights versus privileges issue makes registration far more than a mere infringement.
Information. Registration of a firearm gives the government information that can be used (and has been used, and is being used right now) to confiscate that firearm or to pinpoint its owner for weapon seizure, fining, incarceration, or execution. Having the government in possession of this information is directly contrary to the Second Amendment's intent to ensure that citizens always possess the means to overthrow the government should it become corrupt or tyrannical.
Government control. Allowing the government to seize a citizen's firearm, or to suspend, revoke, or diminish a citizen's ability to defend life, family, property, and country for paperwork omissions or errors, for regulatory violations, for minor infractions of the law, for misdemeanors, or arguably for anything less than conviction for a major crime of violence is also directly contrary to the intent of the Second Amendment. This is because virtually all citizens have committed, or will commit, one or more of the listed non-violent errors listed above, whereas the entire point of the Second Amendment is to place this same citizenry's right to keep and bear arms (and therefore the right of self-defense) out of the government's grasp.
Right versus privilege. Critically relevant to all our rights, is that any edict that attempts to convert a right into a state-granted privilege by imposing prior requirements — such as registration — before it may be exercised goes far beyond mere "infringement" of that right; it becomes an attempt at outright abrogation of the right.
Therefore the state's demand to comply with the requirements of such an edict — no matter how physically easy compliance is — imposes not some mere inconvenience on the individual. It imposes the enormous moral, ethical, intellectual, and spiritual burden of denying the existence of the right.
It does not matter if the state demands that one simply tap one's nose five times in succession in order to be able to keep and bear a particular gun. This would still be a state-mandated prior requirement. Compliance would indicate tacit denial of the validity of the Second Amendment, and denial of the right it protects. Compliance would encompass an implicit acceptance of the right as a mere privilege, which is directly contrary to both the letter and spirit of the Second Amendment.