I know you are specifically talking about a Ruger 10-22,,, but look at this quote from Californias gun laws in reference to AR style weapons.
AK and AR-15 Series Weapons (Kasler v. Lockyer)
This California Supreme Court decision took effect on August 16, 2000. Under this decision, any firearm ofminor variation of the AK or AR-15 type (i.e., series weapon), regardless of the manufacturer, is a Category 2(
Kasler v. Lockyer) assault weapon under the original Roberti-Roos Assault Weapons Control Act of 1989.
All AK and AR-15 series weapons had to be possessed before August 16, 2000 and must have beenregistered on or before January 23, 2001
. The Department of Justice is required to identify these seriesweapons and includes in this publication a listing of identified AK and AR-15 series weapons.
It is important to note that removal of a firearm’s characteristics does not affect its status as a Category2 assault weapon. A Category 2 assault weapon is still an assault weapon even if it has no Category 3(SB 23 - generic characteristics) features.Category 2 assault weapons may be of any caliber, including .22 caliber rimfire.