The best rep range for shoulder press is typically between 5 and 12 reps, with 8-10 being ideal. The reason for this is that lower reps (5-8) will focus more on building strength and muscle, while higher reps (11-12) will focus more on endurance. Additionally, the barbell shoulder press should be performed using a wider grip to shift the stress away from the shoulders and towards the triceps and elbows.