What kind of hassle is involved with bringing a gun with you in your luggage (not carry on) I amagine with all this 9/11 security bussiness it is going to be pain in the ass.

No change since 9-11.  Just declare the firearm, be prepared to show that it is unloaded. and have it in a hard sided case.

is there going to be a problem comming back to california with a Pistol?

I went to BRC with an AR, two pistols and a shotgun in a Pelican.  At Oakland, the clerk didn't even check that they were unloaded.  

In St. Louis, the clerk asked to check that they were unloaded, but didn't have any problem with me taking them back to Kali.

Unless the clerk is a dingleberry, I doubt you'll have problems.  Call your airline to verify their policies beforehand to ensure you won't have trouble.