Bullet: 450 gr TSX  (Barnes)

Diameter: 0.458"

 

Powder: H 335 (Hodgdon)

Starting Powder: 68.5 gr

Max Powder: 72.5 gr

 

Primer: FED 215m

 

Case: Winchester Western

Trim Length: 2.490"

 

Cartridge Overall Length: 3.340"

 

Starting Velocity: 2,076

Starting Pressure:  

Max Velocity: 2,232

Max Pressure:  

 

Compressed
A slight crimp was used to ensure the bullet neck tension was strong enough to keep the bullet from moving
Barrel: 24" with 1:14" twist.

 

Source: https://www.barnesbullets.com/wp-content/uploads/2021/05/458WinchesterMagnum.pdf