Most people often give little thought to barrel length and twist rates, but knowing these specs can help you pair the most suitable bullets to your barrel, and greatly increase your rifles inherent accuracy. In some cases, this knowledge can also help you achieve superior terminal ballistic performance. But what if your rifle isn't new and you are struggling to find out what barrel your precious rifle houses? Follow these steps to determine the approximate twist rate of your barrel.
1. Grab a jag, a patch, and a cleaning rod that spins freely at the handle. The jag and patch should create a snug fit within the barrel.
2. Insert your jag and patch into the barrel from the breech end if possible, to avoid accidentally causing damage to the crown.
3. Wrap a piece of tape around the barrel rod, near the handle. Place a small mark on the tape.
4. Measure the distance from the handle to the barrel.
5. Carefully push the rod down the barrel, allowing the jag to turn freely with the rifle grooves.
6. Keep an eye on the mark and stop pushing once it completes one full revolution.
7. Take a new measurement from the handle to the barrel, and subtract it from the first measurement.
8. The answer will be the denominator of your rifle's twist.
Note: take the measurement in inches, or otherwise remember to convert your answer into inches afterwards. You can use a stiff barrel rod, just make sure you assist it as best as you can as it revolves.
