[Drew68]

That was pure speculation. Someone hypothesized that the reporter mixed up “long rifle” and assumed they meant it as a caliber.

He most likely used an AR-15 chambered in .223.

Why would a mass shooter choose to use anything different? Seriously. Think about it.

It's not these weapons are particularly hard to acquire.

[fightin kentuckian]

“Why would a mass shooter choose to use anything different? Seriously. Think about it.”

But, that assumes he had a logical thought process. He’s a mass murderer, and they don’t have logical thought. You could be right but remember the shooter at the parade in Wisconsin used an “Assault Style “ which was a KelTec Sub 2000, 9mm with 30 round mag sticks.