You never want your barrel to get too hot. Accuracy suffers when barrels over-heat, and excessive heat is not good for barrel life. So how do you monitor your barrel’s temperature? You can check if the barrel is “warm to the touch” — but that method is not particularly precise. There is a better way — using temperature-sensitive strips. McMaster.com (an industrial supply house) offers stick-on temp strips with values from 86° F to 140° F. A pack of ten (10) of these strips (item 59535K13) costs $12.16 — so figure it’ll cost you about $1.20 per barrel for strips. That’s cheap insurance for your precious barrels. For best barrel life, try to stay under 120 degrees F.
Forum member Nomad47 says: “I have temperature strips (bought at McMaster-Carr) on all my barrels. I try not to shoot when the barrel gets to 122 degrees or higher[.]” Here are photos of the McMaster-Carr temp strips on Nomad47’s customized Savage.
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, there’s considerable evidence that 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.
Neconos.com offers Bar-L Benchrest strips that visually display heat readings from 86 to 140 degrees. 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 (86F to 140F) is in the middle. Bar-L temp strips cost $9.00, or $25.00 for a 3-pack.