The man who wrestled the gun away from a Waffle House shooting suspect in Tennessee has said if he was going to die, the gunman would “have to work to kill me”.

Police say James Shaw Junior was a hero for saving lives in the busy restaurant early on Sunday.

But the 29-year-old Nashville resident said he only made a split-second decision to challenge the gunman and save himself from being killed.

Mr Shaw told reporters he had spent the evening at a nightclub and entered the restaurant minutes ahead of the gunman.

Police tape blocks off a Waffle House restaurant. Photo: AAP

He said he and another friend were seated at a counter when he heard gunshots, thinking at first that a stack of plates had crashed down.

Then, he said, restaurant workers scattered and he turned and saw a body near the front door as the gunman burst in.

It was then he realised he had heard gunshots so he jumped up and went behind a swivel door, Mr Shaw said.

“He shot through that door; I’m pretty sure he grazed my arm.

“At that time I made up my mind … that he was going to have to work to kill me.

Mr Shaw said it was then they began wrestling, ignoring his own pain as he grabbed the hot barrel of the AR-15 weapon.

This is the Waffle House hero, James Shaw Jr. He tackled the shooter and saved so many lives in the process. Thank you James. And thank you TriStar Southern Hills Medical Center for your wonderful doctors and nurses who quickly took care of his injuries. pic.twitter.com/kKORfI24G1

— Eugene Gu, MD (@eugenegu) April 22, 2018

“He was kind of cussing while we were wrestling around,” he said.

“When I finally got the gun he was cussing like I was in the wrong.

“It wasn’t any kind of talking between us; I just knew I just had to get that away from him.”

Of the gun, he added: “I grabbed it from him and threw it over the counter top and I just took him with me out the entrance.”

Suspected shooter Travis Reinking was known to police before the deadly shooting. Photo: AP

Mr Shaw said that after getting the man out of the Waffle House, he then ran one way and saw the suspect jogging or trotting another way.

Mr Shaw’s right hand was bandaged at the news conference.

He said he had an apparent bullet graze on one elbow and fell and hit his knee as he escaped.

Mr Shaw said he didn’t see himself as a hero, but felt certain he wouldn’t be alive if he hadn’t succeeded.

“I didn’t really fight that man to save everyone else. That may not be a popular thing,” said Mr Shaw, who went to Tennessee State University and works as a wireless technician for AT&T.

“I took the gun so I could get myself out” of the situation.

But he said he was glad to save other lives as well.

Waffle House chief executive Walter Ehmer joined police officers in thanking Mr Shaw for his bravery.

Hero James Shaw wipes tears away during a press conference on the Waffle House shooting. Photo: AAP

“You don’t get to meet too many heroes in life,” Mr Ehmer said before addressing Mr Shaw, who dabbed at tears in his eyes.

“We are forever in your debt.”

When Mr Shaw’s father went to visit him in the hospital before he was released, he had one piece of advice for his son: “Don’t do that again.”

“I take no pride in him charging a loaded gun,” James Shaw Senior said.

“I do take pride in him helping save the lives of other people.”

After Mr Shaw’s release from hospital, the family went to church together.