Rifle Barrel Twist Rates

Rifle Barrel Twist Rates Available at EABCO

For TC Encore Factory and Custom Barrels, Savage Bolt Guns, Model 97D Rifles and BF Pistols

Available EABCO Twist Rates
The optimum rate of twist for a barrel depends on the particular cartridge, caliber, and bullet weight you are wanting to use. Here are the twists we offer:
.17 Cal - 1:9
.22 RF Cal - 1:16
.22 CF Cal - 1:7, 1:9, 1:12, 1:14
6mm/.243 - 1:8, 1:10, 1:12
6.5mm/.264 - 1:8
.270 Cal - 1:10
7mm/.284 - 1:9
30 Cal - 1:8, 1:10, 1:12
338 Cal - 1:10		 Choosing Your Custom EABCO Twist Rate
You can special order your choice of rifling twist rate when you order a made-to-order Encore Accuracy Barrel.
We have standards we recommend for various chamberings so you don't have to figure this out yourself. But if you'd like to know some guidelines and reasons, here they are: 17 Caliber: Use 1:9 for centerfires. 22 CF (Centerfire): 1:7 is only for the heaviest bullets. 1:12 shoots 40-50gr bullets accurate in 223 and up to 55gr, accurate in 22-250. 1:14 is only for the lightest bullets. 6mm/.243: Use 1:8 for 90-100gr bullets. 1:10 for 75-85gr. Use 1:12 for lightest bullets (ie. 58gr in 6PPC). On 30 calibers, a 1:10 twist is the best all-around. We DO build a few 30's in 1:8 twists for folks who shoot the heaviest bullets. 308 shooters prefer 1:12 for 155 gr bullets. The rule of thumb with twist rates is this: It is better to err on the side of too fast of a twist rather than too slow.
Choice of twist rate is only available when you order a custom barrel or gun made by E. Arthur Brown Company. Thompson Center barrels have standard twists...

Twist Rates for the 308 Winchester... An Example.

  • 1:8 Twist is the fastest twist and is best suited to the heaviest bullets... 180 grain up to 220 gr. and heavier.
  • 1:10 Twist is the best all around sporting/hunting rifle twist rate. It stabilizes anything up to 180 grains which is pretty much all of the hunting ammunition at the local sporting goods store. 150-160 gr would be optimum.
  • 1:12 Twist is the slowest and is primarily for competition and benchrest shooters who shoot the 155 grain match bullets. This twist is best for the lightest bullets up to a maximum of 155 gr bullets.

Rules of Thumb
- It is better to err on the side of too fast rather than too slow on twist rate. Too fast and the bullet still usually shoots fine. But too slow and the bullet will fly sideways and "key hole" in the target.
- Slow 1:12 twist is preferred by competitors who are trying to minimize the smallest imbalances in their bullets. Their goal is to spin the bullet only as fast as it takes to stabilize it and no faster... They are sometimes on the ragged edge which is not the best place to be in a hunting/sporting situation.

All 17 Centerfire 1:10
All 22 Centerfire 1:12
All 6mm/.243 1:10
All 25 Caliber 1:10
All 6.5mm/.264 1:8

All .277 Caliber 1:10
All 7mm/.284 1:9
All 30 Caliber 1:10
All 338 Caliber 1:10
All .375 Caliber 1:12

General TC Twist Rates by Chamber... Scroll Down for Special Pistol Barrel Twist Rates.



Mar 30th 2023 EB

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