Not finding the form on the website. Looking in baggage and special and restricted area and also did a search. Can you provide a link? Thanks!I returned from Africa on April 30 on Qatar as well (JNB - Doha - Montreal), and I echo these comments.
It will take a bit of time, but if your travel agent has ensured that the firearm is mentioned under "Special Remarks" on your reservation, along with the weight of the firearms bag, and you have the "Firearm Surrender" form handy (available on their website) and filled out in advance (except for the signature - they need to see you do that), things will be pretty smooth.
You don't need to have the form in advance - they will have them - but it will just add to the time it takes to check in if you have to start from scratch . . . and in my experience, showing that you are aware of what the procedures are always gives the agent a bit of confidence - they aren't usually as familiar with travelling with firearms as you might expect.