CA laws requires the make, model, caliber and serial number of all handguns authorized to be carried to be printed on the CA LTC permit. [PC 26175(i)]
It's not legal to carry handguns not listed on one's permit or that deviate from what's listed on the permit (example caliber conversions).
Due to the "may issue" CCW issuance system...
CA issuing agencies also have "underground" regulations/restrictions that they have regarding handgun listing on the permits they issue because they need to approve what gets listed on the permit.
Examples...
1. The amount of handguns listed on the permit. Because CA's standardized CCW application only has space to list three handguns, most issuing agencies limits the amount of handguns to three, even though there is no state laws that regulates it (no maximum limit per state laws).
2. Caliber restrictions. Some issuing agencies utilize a minimum and maximum caliber restriction on what handgun gets listed on the permit.
3. Types of handguns. Some issuing agencies do not approve certain types of handguns because they feel they are impractical or not safe.
4. No modifications/alterations. Some issuing agencies will not approve handguns that have been modified (trigger work, laser sights, etc.), which is the same standard they hold their LEOs to.
5. Needs to be registered. Some issuing agencies will not approve handguns that are not registered to the person applying for the permit.
Penal Code 26175
(i) Any license issued upon the application shall set forth the licensee's name, occupation, residence and business address, the licensee's age, height, weight, color of eyes and hair, and the reason for desiring a license to carry the weapon, and shall, in addition, contain a description of the weapon or weapons authorized to be carried, giving the name of the manufacturer, the serial number, and the caliber. The license issued to the licensee may be laminated.