while I do not own a AR, if I did and if I had owned that rifle prior to a new law being passed, I would not worry about it. Clause 3 of Article 1, Section 9 of the Constitution states that Congress is prohibited from passing ex post facto laws. The states are prohibited in clause 1 of Article 1, Section 10. That means that laws cannot be passed that affect a citizen retroactively. The SC has ruled that there are some exceptions where guns and tax's are concerned. Those deal mostly with felons, Tax's, and mental illness. So if you become mentally ill they could require you to give up all of your fire arms or if you were convicted of a felony. In that case, a felon is not allowed to posses a fire arm. Tax's have nothing to do with possession of fire arms, but it is an exception to the constitution regarding the ex post facto rule.

So, if I had an AR, I would not hide it.