Follow up on bullet Stability 300win mag 1-9 twist 26inch

To determine the best bullet for a .300 Winchester Magnum with a 1:9 twist rate and a 26-inch barrel, we need to consider the bullet’s weight, length, and type, as well as the velocity that can be achieved. Here’s a detailed process to identify the suitable bullet:

Bullet Selection Criteria

1. Twist Rate: A 1:9 twist rate is relatively fast, meaning it can stabilize heavier and longer bullets.
2. Caliber: .300 Winchester Magnum (.308 caliber).
3. Barrel Length: A 26-inch barrel can achieve higher velocities, benefiting the stabilization of heavier bullets.
4. Bullet Type: Considering monolithic versus lead core bullets.

Optimal Bullet Weights

For a 1:9 twist rate, you generally want to use bullets that are heavier and longer, as the faster twist rate will stabilize these better. Common weights for .300 Win Mag include:

• 180 grains
• 190 grains
• 200 grains
• 220 grains

Example Calculation for a 200-Grain Bullet

Using the Miller Stability Formula

Let’s assume a 200-grain lead core bullet with an approximate length of 1.5 inches and a muzzle velocity of 2950 fps.

1. Parameters:
   • Caliber (D): 0.308 inches
   • Twist Rate (t): 9 inches (1 turn in 9 inches)
   • Velocity (v): 2950 fps
   • Bullet Length (L): 1.5 inches
   • Bullet Mass (m): 200 grains
2. Calculating Stability Factor (S):

S=30×(200)2×2950(9)2×1.5×(1+(1.5)2(0.308)2)S = \frac{30 \times (200)^2 \times 2950}{(9)^2 \times 1.5 \times (1 + \frac{(1.5)^2}{(0.308)^2})}S=(9)2×1.5×(1+(0.308)2(1.5)2​)30×(200)2×2950​

Let’s calculate this step-by-step.

Step-by-Step Calculation

L=1.50.308=4.87L = \frac{1.5}{0.308} = 4.87L=0.3081.5​=4.87

S=30×2002×295081×1.5×(1+4.872)S = \frac{30 \times 200^2 \times 2950}{81 \times 1.5 \times (1 + 4.87^2)}S=81×1.5×(1+4.872)30×2002×2950​

S=30×40000×295081×1.5×(1+23.72)S = \frac{30 \times 40000 \times 2950}{81 \times 1.5 \times (1 + 23.72)}S=81×1.5×(1+23.72)30×40000×2950​

S=3540000000121.5×24.72S = \frac{3540000000}{121.5 \times 24.72}S=121.5×24.723540000000​

S=35400000003004.68S = \frac{3540000000}{3004.68}S=3004.683540000000​

$S=1178127.1$

Finally:

S=35400000003004.68=1.18S = \frac{3540000000}{3004.68} = 1.18S=3004.683540000000​=1.18

With a stability factor (S) of approximately 1.18, this bullet is close to the lower end of the stable range (1.3 to 2.0), indicating it may be marginally stable. Therefore, it would be beneficial to either:

• Use a slightly lighter bullet (e.g., 180 grains).
• Increase the velocity if possible.
• Choose a longer monolithic bullet that tends to be lighter yet longer.

Recommended Bullets

Based on the criteria and calculations, the following bullets should be well-suited for a .300 Win Mag with a 1:9 twist rate and a 26-inch barrel:

Lead Core Bullets

• Hornady ELD-X 200 grain: High BC and designed for long-range performance.
• Sierra MatchKing 190 grain: Renowned for accuracy in long-range shooting.

Monolithic Bullets

• Barnes LRX 200 grain: Copper bullet offering deep penetration and high weight retention.
• Nosler E-Tip 180 grain: Lead-free with high ballistic coefficients and terminal performance.

Conclusion

For a .300 Winchester Magnum with a 1:9 twist rate and a 26-inch barrel, bullets in the 180-200 grain range are typically well-suited. Both lead core and monolithic bullets have their advantages, so the choice depends 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.