it should concern you that the decision was made by un-elected officials.

It's very much in the same category as other regulatory decisions made that I'm familiar with: what levels of which metals are allowed in water, how much of a drug can be sold and in what amounts, the level of pesticides that can be applied on a farmer's field. In this case, the RCMP have exerted their delegated regulatory authority to make a decision on magazine size.

That's not anti-democratic, that's exactly how the laws and the regulations that implement those laws work in Canada (and commonly elsewhere).

That it's a good idea or not, I don't know. But this hasn't been done in an illegal, immoral or anti-democratic fashion. It's been done through standard government business channels.

Perhaps they could have consulted, or consulted better (regulatory changes can, but aren't always consulted with the public). You always do have the option of getting your member of parliament to tell the RCMP to back off. But the fact that this was "done by un-elected officials" is exactly how regulation in Canada has always worked, and has to work.