See this article from Canada, detailing why their gun rights community faces an uphill battle:
Then there’s the fact that Canada’s got a parliamentary form of government. In the U.S. the NRA can focus its attention on individual legislators, winning them over one by one.
In Canada, representatives have to vote with their party, or else they get kicked out of the party and can’t run in the next election. For Bernardo, that means instead of exerting all his power on one legislator at a time, he has to convince a whole party that his policies make sense.
Our systems has many flaws, but it’s easier for the determined to make a difference, even if they are determined minority. That’s not true in other systems, where political parties tend to dominate the political environment. We tend to think that’s the case here, but it’s not compared to other systems.
It’s also interesting the role campaign finance laws play, but I note Canada’s also apply to how much candidates can spend on elections. I would note that NRA’s model could work even under these limits, since NRA’s political power is more derived from electoral muscle than it’s ability to donate money to favored candidates, and communicate through independent expenditures.