Monitor Ammo/Barrel Heat Levels with Temp-Sensitive Strips
Keeping your loaded cases at a controlled temperature is vital for maintaining good ES and case life. At a late summer varmint match we observed pressure signs with cases that had been sitting in direct sunlight for about 15 minutes. As we were running a “moderate” RL15 load, the pressure indications were surprising. Testing over a chronograph, cases that had been sitting in direct sunlight showed velocities up to 70 fps higher than those that had been kept in the shade. Using QuickLoad’s temperature function, we calculated from the rise in velocities that case pressures had increased by over 4,000 psi–just from 15-20 minutes in direct sunlight!
We will now keep a temp strip in our ammo boxes at all times. Neconos.com offers Bar-L Benchrest temp strips that visually display heat readings from 86 to 140 degrees (our cases got warm to the touch so they were probably about 110-120° F). Think of these strips as compact, unbreakable thermometers. With adhesive backing, they can also be used to monitor barrel heating. Put a strip on the side of the barrel and the barrel’s temp will be indicated by a stripe that changes from black to green. There is also a “general purpose” strip that reads to 196 degrees (bottom row). The Benchrest strip is in the middle.
