GREGG RAINWATER, the mystical half-breed Buck Cross in the ABC series The Young Riders, says that in the fall when it becomes an 8 p.m. show, violence will be toned down. "I'm looking forward to it," commented Rainwater, 24, soft-spoken, gentle actor from Flint, Michigan who admits he's still adjusting to life in LA. "I'd really like to get back to relationship stories as opposed to action stories."

The 5-foot-10, 145 pound actors wears his long hair tied in the back, with an earring dangling from one ear. But after the show has been a couple of years, he warns, he's going to get out the clippers and sheer it off like a sheep until he's completely bald.

Young Riders, produced by David Gerber, made into the fall by the skin of its teeth, having had to buck Cheers all season, it managed to attract a loyal following but ratings weren't that great. On its fall return it will be used as ABC's bait to lure younger viewers to Saturday night lineup beginning with the Western at 8 p.m. followed by China Beach and finally at 10 p.m., by the returning Twin Peaks.

Rainwater, who says he has some Indian blood in him, has one objective when he plays Buck. That, he said, is "not to just do Buck as an Indian, but as a person. Hopefully, then, someone who sees the show who may have some racial prejudices, will think he's pretty okay and carry the attitude into his daily life."

The cast, headed by ANTHONY ZERBE, the way-station manager Teaspoon Hunter, includes STEPHEN BALDWIN (William Cody), YVONNE SUHOR (Lou McCloud), BRET CULLEN (Marshall Sam Cain), JOSH BROLIN (Jimmy Hickock), TY MILLER (the Kid), MELISSA LEO (Emma Shannon) and TRAVIS FINE (Ike McSwain).

Buck, reserved and introspective, adds the balance to the show. "The important thing about him," says Rainwater, "is his spiritual quality everyone can relate to. He's level-headed and clear and his thinking is inspired. He's the sensible one of the young Pony Express riders."

"Too he's faced with the problem of adjusting to the white world, and still retains ties to his Indian background."

The series, not an easy one to make, is filmed in Tucson, a place Rainwater has grown to love. "You've never seen anything until you've seen an Arizona sunset," he says, "but it does get hot! We've worked in 120 degree-heat dressed in our buckskin and flannels and 30 degrees in the wintertime. Sometimes we put in 16 to 18 hours a day."

That's a lot of togetherness for a gang of young men. But Rainwater, who swears on his Indian honor they "never had a fight," hopes to move out of the complex the young actors all shared when the series began and get a little adobe house for himself.

"I'm grateful we all like each other. It's like a family, a real support system, but I've adjusted to Tucson and think I can manage alone."

"I'm planning on giving up my LA apartment, although I have reservations about it. I like to keep my ties to the industry. But I spend so much time in Arizona I want to relate to the community. I'm really getting used to it. It has great bookstores and I've accumulated a lot of books. Plus I'm very interested in ecology."

Establishing roots in LA, he says, hasn't been easy. His apartment is located in an Armenian neighborhood.

"It was a real culture shock going from Michigan to Los Angeles. When you live in a suburb where you go to school with the same people for 13 years, it's like another world to leave it."

"But frankly, I couldn't return to Michigan. I'm always looking around for places I can feel at home. I like Seattle and New York has a lot of great activity and feels good. But at this point I don't feel stuck in any city."

Rainwater was in sixth grade when he saw Oliver in Michigan, and he knew then he wanted to be an actor. He never took his eye off the ball. He acted through high school and later toured England with the warren Youth chorale. But when it was time to head for college on a scholarship (Wayne State University in Detroit), he turned it down, moved to LA and started his acting career.

"I did some theater, including two of Andrew Campbell's plays, the American Basswood and Past Equinox, a drama about Zelda Fitzgerald, after the death of Scott Fitzgerald. I also played Giovanni in the rock musical 'Tis A Pity She's A Whore.

Rainwater believes in research. "I read everything of Scott Fitzgerald's and about his life with Zelda. And for the Young Riders, I did a lot of research about the West. From what I learned it wasn't as violent as it's been depicted."

As soon as he gets a break from filming Young Riders, he said, he's saddling up for a tour of Eastern Europe. He may also have a hidden agenda since the series is now carried in Ireland, England, Spain, Norway and the Netherlands. So, let's be honest, a little promotion won't hurt.

By Kay Gardella, Daily News TV critic