Calibration of Poppers

Initial Calibration

1. Any chronograph, regardless of design, is acceptable for use at all USPSA match levels, as long as the rules and guidelines stated here are followed. Always read, understand, and follow the manufacturer’s recommendations.
2. The Range Master must designate a specific supply of ammunition and one or more firearms to be used as official calibration tools by officials authorized by him to serve as calibration officers.
3. Prior to commencement of a match, the calibration ammunition must be chronographed using the procedure specified in Appendix C2. The calibration ammunition, when tested through each designated firearm, should meet the following criteria:

a. Handguns should achieve a power factor between 115.0 and 125.0 to qualify. 9x19 mm is the recommended caliber.

b. Shotgun Test Gun Specifications: caliber - 12-gauge, maximum barrel length - 26 inches, true cylinder or open choked barrel, any action type.

Test Cartridge Specifications: All ammunition used in a match is required to conform to a minimum PF of 480.

For Birdshot Courses of Fire:

— Diameter of shot to be between #7 (0.10 inch) – #8 (0.09 inch). — Maximum total weight of shot (pellets): 1 ounce. — The manufacturer’s stated velocity is to be less than 1300 fps.

For Buckshot Courses of Fire:

— Shot size OO or local equivalent. — Max of 9 pellets per cartridge. — Manufacturers stated velocity to be between 1120 - 1350 fps (lower velocities in the permitted range are preferred for testing. This equates to a PF of 484 - 584 with 1-ounce loads).

For Slug Courses of Fire:

— Max weight of slug 1 ounce. — Maximum power factor to be less than 590 as calculated from manufacturer’s stated data. (A PF of around 520 or less is preferred).

c. Rifles should achieve a power factor between 140 and 150.

4. Once the supply of ammunition and the designated handguns have been tested and approved by the Range Master, they are not subject to challenge by competitors.
5. The Range Master must arrange for each popper to be calibrated prior to commencement of a match, and whenever required during a match.
6. For initial calibration, each popper must be set to fall when hit within the calibration zone with a single shot fired from a designated handgun using the calibration ammunition. The shot must be fired from the shooting location in the course of fire furthest from the popper being calibrated. Calibration zones are indicated in the diagrams in Appendix B2. Range Master may make initial calibrations by hand. All Poppers shall follow the guidelines below:

a. That a minimum of 50% of the calibration zone (100% for mini poppers) be available at some point in the COF.

b. For handgun, the calibration will be done from a point on the COF where the is available furthest from the popper being calibrated.

c. For shotgun or rifle, the calibration will be done with the applicable calibration firearm or a handgun from a distance of 30 feet.

Calibration Challenges

7. If, during a course of fire, a popper does not fall when hit, a competitor has three alternatives:

a. The popper is shot again until it falls. In this case, no further action is required, and the course of fire is scored “as shot” with the subject popper scored as a hit.

b. The popper is left standing, but the competitor does not challenge the calibration. In this case, no further action is required, and the course of fire is scored “as shot”, with the subject popper scored as a miss.

c. The popper is left standing, and the competitor challenges the calibration. (See Rule

4.3.4 for specifics.) In this case, the popper and the surrounding area on which it stands must not be touched, painted, or interfered with by any person. If a Match Official violates this rule, the competitor must reshoot the course of fire. If the competitor or any other person violates this rule, the popper will be scored as a miss and the rest of the course of fire will be scored “as shot”. If the popper falls for any non-interference reason (e.g. wind action), before it can be calibrated, 4.6 will apply and a reshoot must be ordered.

8. In the absence of any interference, or problem with a target mechanism, the Range Master must first visually inspect the popper for defects or obstructions. If none are found, he must conduct a calibration test of the subject popper (when required under 7c above), from as near as possible to the point from where the competitor shot the popper for handgun, or from a distance of 30 feet for shotgun or rifle. The following will apply:

a. If the first shot fired by the Range Master hits the popper anywhere on its frontal surface and the popper does not fall, the calibration test fails, and the competitor must be ordered to reshoot the course of fire once the popper has been recalibrated.

b. If the first shot fired by the Range Master hits above the calibration zone, the calibration test fails, and the competitor must be ordered to reshoot the course of fire once the popper has been recalibrated.

c. If the first shot fired by the Range Master misses the popper altogether, another shot must be fired until either 8a, 8b, or 8d occurs.

d. If the first shot by the Range Master hits on or below the calibration zone and the popper falls, the Range Master shall require the popper to be reset to its upright position and repeat the calibration process per 8a, 8b, and 8c above. If the popper falls to the calibration shot once again, the popper is deemed to be properly calibrated, and it will be scored as a miss. It is strongly suggested that the RM request the person originally setting the popper to reset it, to determine if that action may have caused the popper to function improperly.

9. Note that authorized metal plates are not subject to calibration or challenge (see Rule 4.3.5).