DougMD & Jollyarcher,

Not certain other than what I read on Winchester's website. Here is what they say about it. It is definitely heavier than lead...

Introducing Winchester® Supreme® Xtended Range Hi-Density shotshells—featuring high density shot that actually performs better than lead by any turkey hunter’s yardstick.

The "Triple Threat" Of Xtended Range Hi-Density Shot:
1. Weighs more than lead.
2. Harder hitting & deeper penetrating.
3. Superior performance at longer ranges.

New Xtended Range Hi-Density shot is 10% denser than lead shot. This characteristic means Xtended Range Hi-Density retains the extra speed and shot weight hunters need to confidently make longer range shots. It also means Xtended Range Hi-Density delivers greater on-target energy and impact performance!

Xtended Range Hi-Density shot uses its high retained velocities and heaviness to surpass lead in long-range effectiveness. Simply put, hunters can now use smaller shot sizes than with lead loads—while effectively bagging turkeys at longer ranges than with lead shot. Plus, Xtended Range Hi-Density turkey loads effectively deliver 25% more pellets on target than lead loads.

This spring season, take advantage of the "triple threat" in Xtended range, bird bagging performance with Xtended Range Hi-Density.