I guess my first question would be what limit? There is no limit in law. I know that some (many?) constabularies try to impose their own limits but in fact they have no right to do so. Those most restrictive constabularies tend to rely on the "Public Safety" card by imposing onerous security requirements. I suggest that you take read of “Firearms Security Handbook” published in 2005. Here's a quote from it: "is not enough to base an assessment on the number of firearms alone".
BTW, as a collector, you do need to show bona fides and I wholeheartedly agree with that requirement.