What are McMillan stocks made of, and what’s inside them?

McMillan stocks are not hollow, and they don’t run on a foam core. That’s a common misconception, and it’s worth clearing up. What’s inside depends on the fill, and the fill is chosen based on caliber, recoil, and intended use.

Edge Tech
Our ultra-light option. Built from carbon fiber cloth, not fiberglass, Edge Tech is the lightest stock pattern we produce.

Standard (Sporter) Fill
The fill used in the majority of our stocks. Solid fiberglass runs through the forearm and action area, with a dense two-part foam in the butt stock. Standard fill is built for calibers up to and including .300 Win Mag.

Magnum Fill
Built for heavy recoil and magnum calibers, primarily on hunting stocks. Constructed the same as standard fill, but with heavier, thicker fiberglass in the recoil lug and action area to handle recoil and keep it manageable on the shooter. Used for anything above .300 Win Mag.

Sniper Fill
Used mainly on magnum calibers in our tactical stocks. Built the same as magnum fill, except the butt stock uses lightweight fiberglass instead of foam, so hardware can be installed if needed. That fiberglass also helps balance rifles carrying larger barrel contours.

And on hunting stocks specifically, some foam is used in targeted areas. That’s by design, to cut weight without cutting performance, not a shortcut.