Legacy Product Notice: The PACT Professional Chronograph is no longer manufactured or serviced by our company. This knowledge base article is provided as a courtesy to customers who still own this product. We cannot provide repairs, replacements, or technical support beyond the information in this article.

PACT Professional Chronograph (Rev. 2.0x)

Product Overview

The PACT Professional Chronograph was a ballistic measurement device manufactured from 1983 to the early 1990s. The last version (Rev 2.0) was released in October 1992. The Professional Chronograph was designed to measure bullet velocity with precision using a dual skyscreen system and included an integrated ballistic calculator.

Key Features

Dual skyscreen system for accurate velocity measurement
Built-in ballistic calculator
Bullet library with common ammunition types
Multiple calculation modes (MAX PB RANGE, SPECIFIC RANGE)
Statistical analysis of shot strings (SD, MAD, ES)
Battery-powered operation (9V alkaline)
Thermal printer for hard copy output

Basic Operation Instructions

Setting Up Your Chronograph

Place the skyscreens 24 inches apart (center to center) in a safe shooting direction.
Connect the START screen to the START port and the STOP screen to the STOP port.
Turn on the Professional Chronograph using the power switch.
Wait for the "FIRE WHEN READY" prompt to appear.
Position the screens so that bullets will pass 5-8 inches above the center of both screens.

SAFETY WARNING: ALWAYS WEAR EYE PROTECTION when using the chronograph. If a bullet strikes a skyscreen or mounting bracket, fragments can cause serious eye injury.

Using the Ballistic Calculator

From the "FIRE WHEN READY" prompt, press "CALC TRAJ" (number 7).
Enter velocity (default is 2500.0 FPS) or accept the default by pressing "SET".
Enter the Ballistic Coefficient when prompted.
For bullet selection, press RVW to access the BC library.
Choose standard (sea level, 59°) or non-standard conditions.
If choosing non-standard, enter altitude and temperature when prompted.
Enter sight height (default is 1.5").
Select zero option (MAX PB RANGE or SPECIFIC RANGE).
Follow the prompts to complete the calculation.

Tip: For field use, the 6-inch vital zone calculation (MAX PB RANGE) is recommended for most hunting applications.

Common Issues and Troubleshooting

Issue	Possible Cause	Solution
No velocity readings	Screens incorrectly connected or low battery	Check that START and STOP screens are connected to correct ports. Replace 9V battery.
Erratic readings	Light conditions or muzzle blast interference	Use diffuser screens, adjust shooting position, or shield screens from direct sunlight.
Inaccurate velocity (too low)	Muzzle blast triggering START screen	Move chronograph further from muzzle or adjust shooting position.
Inaccurate velocity (too high)	Shadow of muzzle blast or sun reflections	Change shooting direction or add shade to the side of screens.
Printer not working	Paper jam or low battery	Replace paper roll or battery. Ensure paper feeds properly.

Battery and Maintenance

The Professional Chronograph operates on a standard 9V alkaline battery. Battery life varies with usage, but is typically best with high-quality batteries like Duracell. To extend battery life, turn off the unit between shooting strings.

Maintenance tips:

Keep skyscreens dry and protected from rain
Store in a dry location when not in use
Protect the unit from extreme temperatures
Keep the printer mechanism clean and free of debris

Paper Replacement

To replace the paper roll:

Remove the six screws from the bottom of the unit
Carefully lift the cover off
Cut the end of the new roll at a 45-degree angle
Thread about six inches through the print mechanism
Place the top back and secure with screws

Special Features in Revision 2.0

The final revision (2.0) of the Professional Chronograph included these enhancements:

Tracks multiple shot strings in memory
Improved prompting in Chronograph mode
John Wootters Lethality Index added to terminal ballistics calculations
"Chronograph Running" startup mode
Extended bullet library with Remington and Hornady ammunition
BC conversion to standard conditions for comparison

Statistical Analysis

The Professional Chronograph provides several statistical measures:

SD (Standard Deviation): Measures consistency of velocities
CV (Coefficient of Variation): SD as percentage of average velocity
MAD (Mean Absolute Deviation): Average variation from mean velocity
ES (Extreme Spread): Difference between highest and lowest velocities

For comparing load consistency, the MAD value is most useful, with lower values indicating better consistency.

Final Notes

While we can no longer service the PACT Professional Chronograph, it was built to be reliable and durable. Many units remain in service despite being manufactured in the early 1990s. The accuracy specifications were typically within ±0.5% under ideal conditions.

This knowledge base article contains the essential information from the original user manual. If you encounter issues beyond what is covered here, we regretfully cannot provide additional support as this product has been discontinued for many years.

Current Products: Please visit our website to learn about our current product offerings that provide modern alternatives with enhanced features and ongoing support.