To determine the optimal bullet weight for a .22-250 Remington with a 1:12 twist rate and a 20-inch barrel, we need to consider the bullet’s weight, length, and type to ensure stability. A 1:12 twist rate is relatively slow and is typically best suited for lighter bullets, especially given the high velocities achievable with the .22-250 Remington cartridge.

### Bullet Selection Criteria

**Twist Rate:**A 1:12 twist rate is slower and stabilizes lighter bullets better.**Caliber:**.22-250 Remington (.224 caliber).**Barrel Length:**A 20-inch barrel is slightly shorter but can still achieve high velocities with the .22-250 cartridge.**Bullet Type:**Considering both monolithic and lead core bullets.

### Optimal Bullet Weights

For a 1:12 twist rate, you generally want to use lighter bullets, as the slower twist rate will stabilize these better. Common weights for .22-250 Remington with a 1:12 twist rate include:

- 40 grains
- 50 grains
- 55 grains

### Example Calculation for a 50-Grain Bullet

#### Using the Miller Stability Formula

Let’s assume a 50-grain lead core bullet with an approximate length of 0.7 inches and a muzzle velocity of 3700 fps.

**Parameters:****Caliber (D):**0.224 inches**Twist Rate (t):**12 inches (1 turn in 12 inches)**Velocity (v):**3700 fps**Bullet Length (L):**0.7 inches**Bullet Mass (m):**50 grains

**Calculating Stability Factor (S):**

$S=()2××(+()2()2 )×()2× $

Let’s calculate this step-by-step.

#### Step-by-Step Calculation

$L=0.2240.7 =3.13$

$S=××(+)×× $

$S=×(+)277500000 $

$S=×277500000 $

$S=1088.64277500000 $

$S=254.91$

Finally:

$S=1088.64277500000 =2.55$

With a stability factor (S) of approximately 2.55, this bullet is in the over-stabilized range. A lower stability factor (closer to 1.5-2.0) would be more ideal, but it still indicates stability.

### Recommended Bullets

Based on the criteria and calculations, the following bullets should be well-suited for a .22-250 Remington with a 1:12 twist rate and a 20-inch barrel:

#### Lead Core Bullets

**Hornady V-Max 50 grain:**Designed for varmint hunting with excellent accuracy and explosive performance.**Sierra BlitzKing 50 grain:**Known for high ballistic coefficients and explosive expansion on impact.

#### Monolithic Bullets

**Barnes TSX 50 grain:**Solid copper with excellent penetration and weight retention, suitable for hunting.**Nosler E-Tip 50 grain:**Lead-free, offering good accuracy and terminal performance.

### Conclusion

For a .22-250 Remington with a 1:12 twist rate and a 20-inch barrel, bullets in the 40-55 grain range are typically well-suited. 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.