Interesting twist on that - the EU has gun regulations, but Czechia made a law that every licensed gun owner in Czechia constitutes a part of the national defense. Sweden has a similar thing, where people in the reserve can have a fully automatic submachine gun. But it's limited to people with an explicit reserve status and the proper training, gun safe etc and further limitations, plus in practice it's not common anymore.
Trust me, if the EU was to interfere with gun ownership here, Czechia would be out the next day. There was a little sign of such thing and a huge protest was planned within days, forcing the politicians to consider protecting gun ownership/carrying in the constitution (not yet done, but still on the table)