Monitor Barrel Temps with Heat-Sensitive Strips

Many parts of the country are experiencing a heat wave right now. It was 117° F in Las Vegas yesterday. Unfortunately, this is “prime time” for shooting matches, so competitors may have no choice but to shoot in very hot weather. When ambient temperatures soar into the 100s, you need to be especially careful about barrel heat. Bad things can happen if your barrel gets too hot. First, with some barrels, the point of impact (POI) will shift or “walk” as the barrel heats up excessively. Second, even if the POI doesn’t change, the groups can open up dramatically when the barrel gets too hot. Third, if the barrel is very hot, the chamber will transfer heat to your loaded cartridge, which can lead to pressure issues. Finally, hot barrels wear out faster. This is a very real concern, particularly for varmint shooters who may shoot hundreds of rounds in a day. For this reason, many varminters switch among various guns, never letting a particular barrel get too hot.

How do you monitor your barrel temperature other than guessing by “feel”? BAR-L Benchrest strips visually display heat readings from 86 to 140 degrees F. Think of these strips as compact, unbreakable thermometers. These adhesive-backed strips can 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. These strips are easy to read. The green box displays the current temperature of the barrel in both °F and °C. We recommend using the Benchrest strip (86F to 140F), shown in the middle. There is also a “General Purpose” strip that reads to 196 degrees (bottom row).

Installation: Before placing the temp strips on your barrel, clean and degrease the barrel with alcohol for better adhesion. Once in place, the plastic-covered strips should provide years of service. Note, we do not recommend use with high-polished blued barrels.

Controlling Ammunition Temperature is Important Too
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! Accordingly, you’ll want to keep your ammo out of the sun, in an insulated container. The Igloo Ice Cube MaxCold 70 Roller Cooler can hold enough ammo for a multi-day varmint safari or a week at Camp Perry. It’s large enough to also store water bottles and cold beverages.