La Mesa Collectibles is the place in El Cajon mentioned above. Haven't been there in a while, but bought some powder there a while back and the pricing was reasonable. Not sure about the local ordnances restricting component inventory - wouldn't surprise me, though as there is no limit to the idiotic, useless, and unconstitutional restrictions put in place in CA regarding firearms (as most here are aware). I thought that store's problem was more a financial one in maintaining large inventory, but I could be wrong about that.
A new shop called Big Shot on Miramar Road (right across from the Marine base) intends to stock components, and had a few last time I was there. They told me they have placed large orders but of course timing of delivery was unknown.
But it you're from AZ, I would think you'd be much better off shopping at home. Can't recall the name but someone at a local range once described a Phoenix-area store that had a very wide range of components for sale. Or if you can afford them just jump on the stuff available online as noted in bds' great component availability thread. Seems there is a bit of almost everything showing up again (if only for minutes!).
The closest component sources are up in Orange County and around LA - and not so many of those, either. But Welding Rod there are plenty of shooters in SD County (two new ranges plan to open up soon, and several new gun stores over that last few years, though pretty much just Evil Black Rifle shops, not full-range gun shops). The outlook is grim, though, as the lawlessness, bigotry, ignorance, and authoritarianism of the Coastal Clueless are now closing in common sense constitutional firearms ownership.