What NRR do I need for shooting and loud power equipment?

Reviewers across r/guns and r/NoobGunOwners repeatedly note that most muffs landing in the 22-26 dB NRR range are adequate for outdoor shooting, while indoor ranges and very loud equipment benefit from higher passive ratings (33-37 NRR) or doubling up muffs over foam plugs. Community consensus also cautions that printed NRR figures are lab-derived and real-world fit matters more than the number on the box.