What You Need To Know About Bullet Stability and Barrel Twist Rate — What You Should Know

December 28, 2022Understanding twist: Bullet stabilizationby Paul Box, Sierra Bullets Ballistic Technician, for Sierra Bullets Blog. Based on the questions we receive on a daily basis via our 800 (Customer Support), line, twist is one the most misunderstood topics in the gun industry. Let’s dig deeper into the mystery of twist and gain a better understanding what it means. (1-14) or 1:19? What does this actually mean? A rifle with a 1:14 rating? Twist means that the bullet will turn one revolution every fourteen inches. A 1:9? It turns once every nine inches it travels down the barrel. This is the problem that some people have difficulty with. I’ve received calls from shooters who thought a 1:14 was faster than a 1:9? A 1:14 twist was faster than a 1:19? Because the number was higher with the 1:14?. This is because a shooter with a.223 and a 1:8 twist rate, is the most common misconception. His rifle will not stabilize a 55gr bullet, or anything lighter. Let’s take a look at what is needed. The faster a bullet’s diameter is, the more twist must be done to stabilize it. The.223 has a 1:8 twist. This was to stabilize 80gr bullets with this diameter. The truth is that the opposite is true. A 1:8? A 1:8? Over-spinning a bullet with good concentricity will not affect its accuracy potential. Editor’s Note: The faster twist rate will not normally decrease velocity. Bryan Litz’s Applied Ballistics Labs has confirmed this. It is possible to experience some speed loss.
Many barrel-makers mark the bore dimensions and twist rate on their blanks. After balancing your tires properly at the tire shop and putting them on your truck, you can drive down a street at 35 MPH with perfect spin. They will still spin perfectly even if you drive 65 MPH on the highway. The same thing happens with a bullet. I once loaded 35gr HP bullets into a 22-250 Ackley with an 1:8? twist. After three shots, the average velocity was 4584 FPS and an RPM level 412,560. The group was.750? at 100 yards. This illustrates that it is difficult to over-stabilize good bullets. Twist-rate illustration by Erik Dahlberg, FireArmsID.com. Photo of Krieger barrel courtesy GS Arizona.Similar posts:Tags:Barrel Twist Rate. Bryan Litz. Bullet Stability. Sierra Bullets. Velocity.