I have a deep respect for your constitution and it's ideas of freedom, - but it is a product of the times, where every weapon available was a front-loaded monstrosity that took forever to re-load. If guns worked the same way now then by all means keep all the guns you like... :-) They do not work like that anymore and the cost of manufacture has also diminished considerably so access is now ubiquitous, which leads to the problem you are having. The spirit of the constitution* could be upheld if you ban, confiscate and melt all weapons not used for hunting/sport - meaning all weapons capable of firing more than two rounds before re-loading. Granted - it would take some time and there would be a LOT of shouting, but in the end it would work...

There you go - Problem solved...

* If (big IF) the populace is SO annoyed with government that they are prepared to take up arms against the government, then everybody has got bigger problems and I am sure that at least some fractions of the police/military would help in the overthrow of the unpopular government ;-) That is how revolutions take place everywhere else :-)