Wislon Combat Loaded Ammunition- .458 Socom 300gr TTSX!

Was this bullet purpose built for the socom? Or is it just the socom .458 ttsx? Im just wondering, because the velocity on the box seems to be pretty close to the minimum velocity needed for expansion. Do you have the numbers on minimum velocity needed for expansion?
Yes,
This bullet was designed with the .458 SOCOM in mind, and has a minimum expansion threshold of 1300 fps. It is a HAMMER.
Thanks for the info
Are you guys offering brass only by chance?
I love this round!