Warframe Mastery and Weapons Question

[Ober Kommandant Fraus Grutz]

I have the Bo (Staff) and Im leveling it up to 30 for master points. After I achieve level 30, If I convert it into the Cadus, will I lose the mastery points for the Bo since it is a component of the cadus and I will lose the Bo? Thanks

[Basan™]

You'll lose the Bo but retain the mastery for it. And you'll have to start over with the Cadus since it'll be a new weapon made from parts of others.
And, for instance, similar goes for the Hikou being a construction element for either the Panthera or the Mitter (because without seeing the 'UnOfficial WarFrame (WF) Wiki'[warframe.fandom.com] I'm never too sure on why I'm retaining low level weapons that already mastered eons ago).

For a comparing ex., if later on you manage to get a Bo Prime staff you'll also will have to master it because different versions of the same weapon upon WF also count as different weapons.

[Firefrye]

You earn 3000 mastery points for every unique weapon you reach level 30 with regardless of if you keep the actual weapon once you are done.

Frames/companions/vehicles all give 6k.

Primes and other "variants" of any item earn separate mastery.

There are a few special weapons or weapon categories that act differently:
1. Modular weapons that you can build from parts in the towns of each open world have to be leveled twice to earn mastery. Once to "gild" them (which then allows you to add a catalyst and significantly boost their stats) and again to actually earn mastery for them.
2. Weapons from the "nemesis" enemies you encounter can earn up to 4k. Each time they hit max rank, if you forma them they can gain an additional two levels (up to a level cap of 40 rather than the typical 30).
3. There are one or two other weapon exceptions I won't mention due to being direct spoilers.

Necramechs are a special vehicle you encounter in late quests and on Deimos. They can be leveled to 40 like the nemesis weapons and earn 8k mastery.

Every node you complete on the star chart earns a small number of points.

Junctions give 1k

Every rank in the "intrinsics skill trees" for Railjack or Duviri earn 1.5k

You can never "waste" mastery. Even if you are ready to Rank up, any "extra" mastery will still be earned and count towards your next rank whenever you finish your current mastery test. You could theoretically save up multiple mastery ranks worth a time and run multiple tests back-to-back. (I have no idea what would make you do that... but you could.)

Your mastery progress can be viewed in your profile, and some of it is repeated in the codex.