The Beretta PX4 Storm is the mechanical outlier in the .40 S&W service pistol category. Where every other gun here uses a Browning tilt-barrel locking system, the PX4 uses a rotating barrel — the barrel rotates as the slide cycles rather than tilting down at the rear. The result, by community consensus among PX4 owners, is noticeably softer felt recoil than other full-size .40s. At 28.57 oz it's not the lightest option, but the rotating action distributes the recoil impulse differently than a tilt-barrel design and the difference is consistently reported as real, not marginal.

The other major departure is the action: the PX4 is DA/SA with an ambidextrous decocker/safety lever. The first shot from a hammer-down carry position is double-action at a longer, heavier pull. After the first round fires, the hammer stays cocked and the remaining shots are single-action — the 4.5 lb spec pull applies to those SA shots, which is the lightest SA trigger in this group. Buyers coming from striker-fired pistols (Glock, M&P, VP40) will need to spend time learning the manual of arms. The decocker lever is meant to be swept down to drop the hammer safely from cocked SA back to DA — it is not meant to be held or ridden as a standard safety.

.40 S&W is in commercial decline, and the PX4 Storm is a niche choice even within that declining caliber. The buyer profile here is someone who specifically wants DA/SA operation, prefers the softer recoil of the rotating barrel, and is willing to invest time in learning the decocker manual of arms. If you're used to striker-fired pistols and mainly want a .40 for range work, a polymer-frame striker like the G22 or M&P 40 is a simpler starting point. The PX4's rotating barrel is the real strength; the DA/SA transition is the real hurdle.