This guide will let you know where to get Searing steel and Magma Chamber in Warframe.
Starting steel and Magma chamber can drop as a reward for completing the Razorback Armada mission. It is a limited-time event that only comes often, and you need a Razorback Cipher to enter the mission.
It is recommended to have high damage weapons/frames or tanky frames, rhino, chroma, ash (Naros, mesa, etc).
Both of the mods have amongst the lowest drop rates out of all the items in the reward pool; it’s probably going to take you some runs, more or less, until you get either of the mods.
The other way you can get Searing steel or Magma chamber is by running specific rail jack missions, and they only drop from one specific enemy that can spawn in these missions.
You have to run the rail jack nodes that have a chance at spawning grineer galleons. Earth Proxima, Korms belt can spawn grineer galleons when running the mission, and if it doesn’t spawn when you run the mission, then you can leave the mission and go back in until you get a grineer galleon to spawn.
Once you get in the rail jack mission, you will know if there’s a galleon in the mission or not, as the game will show alongside your other objectives in the mission to kill a galleon captain. Two types of captains can spawn on the ship: the Pye captain, the gun, and The Beite captain, which has the sword. You have to look for the Pye captains because he has a chance to drop the mods when killed.