Back Up Gun (BUG) All CoF for the Back-Up Gun Division must be limited to five (5) rounds maximum per string (no reloads on the clock) to allow autos and revolver shooters to compete equally. Handguns permitted for use in this division must: A. Be single or double action. B. Be either pistol or revolver. C. Be .32 auto or larger. D. Have a barrel length: 1. Semi-automatic, 3.8? or less (factory installed cone style barrels with or without a barrel bushing are permitted). 2. Revolver 3? or less. E. Maximum (total) number of rounds that may be loaded into the handgun is five (5).