Seventeen rounds of 9mm in a gun that weighs 21.5 oz and measures 1.1 inches wide. The X-Macro is Sig's answer to the question of how much capacity can fit in a concealable frame before the grip becomes too tall for practical carry. The integrated compensator vents gas upward through ports in the slide to reduce muzzle flip, which matters more with the 3.1-inch barrel than it would on a longer gun. XRAY3 tritium sights and an optics-ready slide come standard. The standard M1913 Picatinny rail is an upgrade over the proprietary Sig rail on the P365 XL, opening up more weapon light options.

The 3.1-inch barrel is the shortest in the compact class. That costs velocity compared to 4-inch barrels, with published chronograph data showing 75-100 fps less with defensive loads. The Beretta APX A1 Compact holds 15 rounds with a 3.7-inch barrel at similar weight, giving up 2 rounds but gaining barrel length. The Springfield Hellcat Pro matches 15 rounds in a slimmer package but cannot touch the X-Macro's 17-round capacity. The X-Macro does one thing no other compact 9mm does: it puts 17 rounds in a 1.1-inch-wide frame light enough to carry every day. That specific combination of capacity and concealability is unmatched.