UML rules
6.4. Limited
6.4.1. Pistol
6.4.1.1. Custom or factory installed electronic sights, optical sights, compensators or barrel porting are prohibited.
6.4.1.2. Magazines shall not exceed 171.25 mm OAL (overall length) for single stacks, and shall not exceed 141.25 OAL
for staggered magazines.
6.4.1.2.1. Pistol Magazine failing the OAL inspection, after the competitor has completed one or more stages, will
result in the shooter being bumped to Open.
6.4.1.3. Pistol caliber shall not be changed during the event
6.5. Tactical Optics
6.5.1. Pistol
6.5.1.1. Custom or factory installed electronic sights, optical sights, compensators or barrel porting are prohibited.
6.5.1.2. Magazines shall not exceed 171.25 mm OAL (overall length) for single stacks, and shall not exceed 141.25 OAL
for staggered magazines.
6.5.1.2.1. Pistol Magazine failing the OAL inspection, after the competitor has completed one or more stages, will
result in the shooter being bumped to Open.
6.5.1.3. Pistol caliber shall not be changed during the event
Thanks Dan I think I found the answer to my question.