Grampa, I shoot at Firing Line and Evans Gunsmithing fairly often--but only with a handgun. Have shot at the old Olympic venue that you mention, but only with a shotgun. For rifles it seems one has two choices: a short drive to a too-short range like Evans (But what can you accomplish beyond the most basic zeroing at 25 yds or a long drive to the desert BLM land, or up to the Nat. Forest in Ventura County, or to Burro Canyon (not on weekends, thank you very much) or "A Place to Shoot" in San Francisquito Canyon. I prefer the latter, but unless you stay in a motel, it's a pretty tiring day getting up there before the commuters clog the freeways, shooting from 9am to 1pm, then back thru LA to Seal Beach. The motel is probably worth it--you can get in an afternoon/evening and a long morning, and still get home unbushed.
If you go to San Francisquito, watch out for rattlers. They got 'em. If you ever want to carpool up there or have a better place in mind, email me at g.armstrong@hvcc.edu
Mike Armstrong