I USUALLY LEAVE BIRTHDAYS and anniversaries to others, but one such observance caught my eye last week. Charles Bronson is about to turn 80.

Bronson at 80! Unreal! How could that stony-faced gunslinger in “Once Upon a Time in the West” be 80?

Bronson was a throwback to another era in Hollywood, before all the actors looked like they were refugees from “Dawson’s Creek.” A one-time coal miner, Bronson wasn’t born, he was chiseled. He had acetylene torches for eyes. His roots and influences harken back to the era of Bogart, Garfield and Raft. Leading men back then didn’t need lines; they had looks.

Charlie Bronson was never much of a talker, as I was reminded the other day over dinner. Approaching 80, he still walks with that don’t-mess-with-me swagger. He doesn’t act anymore. Why should he?

The reason I’m writing this, however, is that I know his dirty little secret. You see, Charlie may look homicidal, but in reality he’s all heart.

The reason we were celebrating the other day is that his daughter, Katrina Holden Bronson, a lissome and talented 27-year-old, won the emerging director award for her short film. The prize was awarded by the Media Trust at the Malibu Film Festival and Charlie Bronson was teary-eyed at the awards ceremony. Called “Righteous Indignation,” it’s a spirited film, and if he was proud, so was I.

Charlie adopted Katrina when she was a sprightly, delightful 11-year-old. Her mother, a British-born casting director and single mother named Hilary Holden, had died of a sudden heart attack, and Katrina was orphaned. Hilary had moved around a great deal in her life, and there were no close relatives. In fact, it quickly became clear that only two couples were in a position to adopt Katrina — Charlie and his wife, the late Jill Ireland, or my wife, Blackie, and I. Charlie already had a raft of kids, so he seemed an unlikely candidate.

AND THAT’S WHEN I FIRST LEARNED Charlie’s secret. A big-hearted man, he was not only willing to adopt Katrina — he was thrilled by the prospect. At Hilary Holden’s funeral, I saw Katrina’s small frame disappear into Bronson’s long black limousine. She looked scared and very much alone.

Jill Ireland was as compassionate and gracious as her husband, and they provided a warm home for Katrina. Despite Bronson’s fame, however, theirs was not an easy road. Jill fought cancer for several years, finally succumbing in 1990. One of their sons, Jason, died of a heroin overdose the year before at age 27. A diligent activist, Jill wrote books about Jason’s battle, and then hers. Charlie remarried in 1998 to singer Kim Weeks.

Katrina, meanwhile, went on to UCLA and the Sorbonne in Paris and then decided to become a writer-director. She seems well on her way.

And flinty-eyed old Charlie is very proud of her. He’s made her road a lot easier than his.

BORN CHARLES BUCHINSKY, Charlie was saved from the coal mines by World War II. He tried his hand at acting at the old Pasadena Playhouse and got his first film role in 1951 in a movie called “You’re in the Navy Now.” Two guys named Lee Marvin and Jack Warden also bowed in that movie.

It seemed unlikely that a coal miner would make his mark in Europe, but that’s what happened to Charlie. To the great Sergio Leone, Bronson’s leathery, oddly taciturn demeanor perfectly represented his view of the Western gunslinger. “Once Upon a Time in the West” made Charlie a legend in Europe. American filmmakers, too, realized that Bronson’s riveting persona was perfect for ensemble action pictures like “The Magnificent Seven,” “The Great Escape” or “The Dirty Dozen.” He might have only a few lines, but you wouldn’t forget him.

Some looked askance at his “Death Wish” movies, dealing with a man who took the law into his own hands, but they were mild compared with “Dirty Harry.”

“Audiences like to see the heavies get their comeuppance,” Bronson once told an interviewer. That’s about all he told him. He didn’t like to talk about himself.

After all, why should he? He’s got the “look.” And the heart to go with it.

Happy birthday, Charlie.