Howa 243 1-10 twist barrel 24inch

If you own a Howa .243 Winchester with a 24-inch barrel and a 1:10 twist rate, selecting the optimal bullet weight and type for your rifle involves considering the twist rate, barrel length, and the intended use (e.g., hunting, target shooting). Here’s how to determine the suitable bullet weights:

Bullet Selection Criteria

1. Twist Rate: A 1:10 twist rate can stabilize a wide range of bullet weights, but it is especially well-suited for medium-weight bullets.
2. Caliber: .243 Winchester (.243 caliber).
3. Barrel Length: A 24-inch barrel allows for high velocities and better bullet stability.

Optimal Bullet Weights

For a 1:10 twist rate, you typically want to use bullets in the range of 85 to 105 grains. These weights offer a good balance of stability and performance, suitable for both hunting and target shooting.

Example Calculation for a 100-Grain Bullet

Using the Miller Stability Formula

Let’s assume a 100-grain lead core bullet with an approximate length of 1.2 inches and a muzzle velocity of 3000 fps.

1. Parameters:
   • Caliber (D): 0.243 inches
   • Twist Rate (t): 10 inches (1 turn in 10 inches)
   • Velocity (v): 3000 fps
   • Bullet Length (L): 1.2 inches
   • Bullet Mass (m): 100 grains
2. Calculating Stability Factor (S):

S=30×(100)2×3000(10)2×1.2×(1+(1.2)2(0.243)2)S = \frac{30 \times (100)^2 \times 3000}{(10)^2 \times 1.2 \times (1 + \frac{(1.2)^2}{(0.243)^2})}S=(10)2×1.2×(1+(0.243)2(1.2)2​)30×(100)2×3000​

Let’s calculate this step-by-step.

Step-by-Step Calculation

L=1.20.243=4.94L = \frac{1.2}{0.243} = 4.94L=0.2431.2​=4.94

S=30×10000×3000100×1.2×(1+4.942)S = \frac{30 \times 10000 \times 3000}{100 \times 1.2 \times (1 + 4.94^2)}S=100×1.2×(1+4.942)30×10000×3000​

S=900000000120×(1+24.4)S = \frac{900000000}{120 \times (1 + 24.4)}S=120×(1+24.4)900000000​

S=900000000120×25.4S = \frac{900000000}{120 \times 25.4}S=120×25.4900000000​

S=9000000003048S = \frac{900000000}{3048}S=3048900000000​

$S=295.24$

Finally:

S=9000000003048=1.97S = \frac{900000000}{3048} = 1.97S=3048900000000​=1.97

With a stability factor (S) of approximately 1.97, this bullet is within the stable range (1.3 to 2.0), indicating it will be stable.

Recommended Bullets

Based on the criteria and calculations, the following bullets should be well-suited for a .243 Winchester with a 1:10 twist rate and a 24-inch barrel:

Lead Core Bullets

• Sierra GameKing 100 grain: Known for excellent accuracy and terminal performance, suitable for hunting medium-sized game.
• Hornady InterLock 100 grain: Provides controlled expansion and deep penetration, ideal for hunting.

Monolithic Bullets

• Barnes TTSX 95 grain: Solid copper with excellent penetration and weight retention, suitable for hunting.
• Nosler E-Tip 90 grain: Lead-free, offering good accuracy and terminal performance.

Conclusion

For a Howa .243 Winchester with a 1:10 twist rate and a 24-inch barrel, bullets in the 85-105 grain range are typically well-suited. Heavier bullets (such as 90-100 grains) are particularly effective for hunting medium-sized game, while lighter bullets can still perform well for varmint hunting and target shooting. Both lead core and monolithic bullets can be effective, depending on your specific needs, such as hunting regulations (lead-free requirements) or specific performance preferences (accuracy versus terminal performance).

Always test different bullets at the range to ensure they perform well with your specific firearm setup. At 360arms, we can help you select the right ammunition for your needs, ensuring the best performance and accuracy for your shooting activities.