Engineered for Lethal Performance Inside 40–45 Yards
Legacy was built around a simple goal:
Deliver maximum lethal efficiency within real-world hunting distances.
Legacy began with bismuth - the shell that defined Boss and proved that thoughtful engineering could outperform conventional assumptions. CuProX™ carries that same philosophy forward, refining performance through aerodynamics and efficiency while staying true to the foundation that built the brand.
Running CuProX at 1350 fps places the pellet within an optimized velocity window - balancing pellet energy, pattern density, and aerodynamic efficiency to produce consistent terminal performance where most shots actually happen.
This isn’t about chasing velocity.
It’s about delivering dependable lethality inside 40–45 yards.
For the same shot size:
• Steel often relies on higher muzzle velocity (such as 1500 fps) to compensate for lower density, but sheds energy quickly due to higher drag.
• Boss Bismuth established the Legacy standard through density and proven field performance.
• CuProX™ builds on that foundation by improving aerodynamic efficiency, allowing more usable pellet energy to be retained within the effective range envelope.
At typical Legacy distances:
• CuProX at 1350 fps delivers approximately 18% more retained pellet energy than steel at 1500 fps, despite the lower muzzle velocity.
• CuProX delivers approximately 4% more retained pellet energy than Boss Bismuth at 1350 fps, reinforcing Legacy’s reputation for reliable lethality.
Pattern Control Where It Matters
Legacy with CuProX is engineered for predictable performance across a wide range of choke configurations.
Choke it as tight or as open as conditions demand.
• With full chokes, shooters can expect 40-yard patterns approaching 85% or better — representing up to a 15% improvement over Legacy Bismuth.
• For tighter shots, opening the choke produces larger, dense, uniform patterns, maintaining consistency through aerodynamic stability rather than excessive velocity.
*Until March 15th, get a Boss Factory Performance Choke for just $30 with the purchase of a case of Boss loaded with CuProX™.*
Grab yours here.
CuProX maintains pellet integrity on impact, eliminating the fragmentation sometimes associated with bismuth while delivering consistent penetration.
Deadlier by Design.
Corrosion-Inhibited Copper shot was deemed non-toxic in 2013 by the USFWS. Once our Mark III tester is approved by the USFWS we anticipate an updated formal approval to be added to the USFWS Approved Shot List.
This shell is built according to SAAMI specs. The Turkish semi-auto .410’s have had issues cycling our shells. We have been working diligently with the manufacturer to come up with a solution that allows 100% of the guns to function with 100% of our shells. We suggest the use of these shells in pump, side-by-side, and over/under shotguns only.
