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The terrorist who murdered 49 people at a gay nightclub in Orlando last weekend used a Sig Sauer MCX rifle, not an AR-15, Steve Harrigan reported this afternoon. 

Harrigan described the Sig Sauer MCX as a lightweight, powerful rifle that weighs six pounds and was originally designed for use by Special Forces. 

Mateen purchased the Sig Sauer .223 caliber rifle legally at a Florida gun shop, St. Lucie Gun Sales, on June 4. He purchased a Glock 17 handgun the next day, passing background checks both times.

The maker of the Sig Sauer firearm says an experienced shooter can fire up to 45 rounds in a minute with the rifle. Police believe Mateen used the Sig Sauer to do most of the killing.

The AR-15 rifle is often brought up by gun control supporters who want to see sales to civilians prohibited by Congress as part of a larger assault weapons ban. 

President Obama and Hillary Clinton have both called for stricter gun control laws in the wake of the Orlando attack.

On Capitol Hill today, Sen. Chris Murphy (D-CT) started a talking filibuster in an effort to get Republicans to consider legislation on expanded background checks and ensuring those on terror watch lists cannot buy guns.

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