[real saxophonist]

An accessory rail for attaching accessories. Wow, that Peter Suciu sure knows his stuff!

[T.B. Yoits]

...the forensics teams couldn't determine which bullet came from which officer's Glock, because the polygonal rifling didn't leave enough uniquely distinguishing marks on the projectile. All of the recovered bullets looked too similar.

The bullets did not seal well in the barrel and delivered less power than if they did. Outside of a smooth bore (with a bullet with less power because it's not spinning), lack of grooves on a bullet means it was slightly undersized for the barrel.

A polygonal barrel would have more gas escaping around the bullet than a standard barrel.