Here's a visualization of what exactly got nerfed with Luke's medium Sand Blaster projectile in the Street Fighter 5 patch - EventHubs

According to the patch notes, Luke's medium Sand Blaster has had its active frames reduced from 7 frames to 6 frames.

For comparison, the light Sand Blaster still has 5 active frames while the heavy version of the beam projectile still has 9 active frames.

Theoretically, this means that Luke's medium Sand Blaster has had its range reduced by one-seventh of what it was before.