BR 30 or BR 40 bulbs can be easily fitted into any household fixture including a lamp. But, the light reflected by these bulbs is directional i.e. the beam of light is focused straight ahead. So, they are best suited for recessed lighting either in the ceiling or in walls. A lamp requires a bulb that would spread light in all directions. So, it won’t be an intelligent decision to use BR 30 bulb in a lamp.