IMO, some government laws may need to be disobeyed in order to obey God. One example that comes to mind would be mandating medical people to perform abortions, with no "conscience clause". Others would be as related to Acts 3 and 4, if (when?) the government would outlaw biblical preaching. And like Peter, John and Paul (and many others down to this day), Christians must be ready to take the consequences of such disobedience.
How would I react to a firearms prohibition/confiscation law? Since I wouldn't know the sociopolitical situation at that time, I can't say. If it was done by a stable democratic (small "d") government, I'd likely need to obey (after much prayer). If it was a tyrannical government acting like, say, current Myanmar (army shooting non-protesting citizens in the streets), it would be a much different choice.