Bullet: 80 gr Tipped TSX  (Barnes)

Diameter: 0.257"

 

Powder: H380 (Hodgdon)

Starting Powder: 43.0 gr

Max Powder: 47.0 gr

 

Primer: FED 210

 

Case: Winchester Western

Trim Length: 2.223"

 

Cartridge Overall Length: 2.830"

 

Starting Velocity: 3,108

Starting Pressure:  

Max Velocity: 3,415

Max Pressure:  

 

*Load data for this cartridge was tested at the standard SAAMI pressure level—not the higher +P pressure levels listed in some manuals.
Barrel: 24" with 1:10" twist.

 

Source: https://www.barnesbullets.com/wp-content/uploads/2021/05/257Roberts.pdf