Step 1: Add lower-body strength
Heavy goblet squats, Bulgarian split squats, and single-leg RDLs. Range is a force problem before it's a form problem.
Step 2: Use your legs, not your arms
Same shot motion, more leg drive. If your form changes as you back up, you're cheating with your arms — and your accuracy will collapse.
Step 3: 1-foot range progression
Move back one foot per week. Make 5 in a row before moving back. Slow, brutal, but it's the only progression that holds up under fatigue.