Customers shop at a Dick’s Sporting Goods store in Niles, Ill., in 2014. The sports retailer CEO Ed Stack announced Dick’s is immediately ending its sales of assault-style rifles and requiring all customers to be older than 21 to buy a firearm at its stores.

Customers shop at a Dick's Sporting Goods store in Niles, Ill., in 2014. The sports retailer CEO Ed Stack announced Dick's is immediately ending its sales of assault-style rifles and requiring all customers to be older than 21 to buy a firearm at its stores.

Customers shop at a Dick’s Sporting Goods store in Niles, Ill., in 2014. The sports retailer CEO Ed Stack announced Dick’s is immediately ending its sales of assault-style rifles and requiring all customers to be older than 21 to buy a firearm at its stores.

Customers shop at a Dick’s Sporting Goods store in Niles, Ill., in 2014. The sports retailer CEO Ed Stack announced Dick’s is immediately ending its sales of assault-style rifles and requiring all customers to be older than 21 to buy a firearm at its sto