The US Palm Storm CAT4 Pistol

Overview of the US Palm Storm CAT4 Pistol

The video focuses on the US Palm Storm CAT4 pistol, a 5.56 NATO AR-15 pattern firearm that parallels the previously reviewed CAT4 rifle but with a shorter barrel and brace instead of a stock. The host notes that this pistol is intended to feel like a premium rifle at a lower price point, positioned under brands such as Geissele, Daniel Defense, and HK. The pistol is priced around $1,399. The discussion will cover technical specifications, distinguishing features, and initial shooting impressions, with more extensive testing planned for a future, dedicated review.

Barrel, muzzle brake, and core specifications

The CAT4 pistol uses an 11.5-inch cold hammer forged barrel in 5.56 NATO, described as a sweet spot compared to 10.3-inch setups. It features a proprietary muzzle brake that is claimed to eliminate flash. The host has only shot it in daylight so far and did not observe a fireball, but has not yet tested it in low light. Overall length is about 29 inches collapsed and 32.3 inches extended, with a height of 7.3 inches and width of roughly 2.7 inches. Unloaded weight is about 6 pounds. The barrel has a 1:7 twist rate and 1/2x28 thread pitch, aligning it with common 5.56 muzzle device standards.

Handguard lockup, rail design, and upper receiver

A key feature is the proprietary handguard lockup system, described as nearly monolithic. The handguard secures to a single rear mounting pad with two screws and uses triangular side tabs that interface with cuts in the upper receiver, rather than a front tab. The bottom is flattened where it meets the upper, producing a very solid, movement-free lockup that will be evaluated further over time. The pistol has a full-length Picatinny top rail and a seven-sided M-LOK handguard similar to what is seen on some Geissele rails, offering a thin profile and multiple mounting options. The upper receiver itself is noticeably beefier, with more angular, polygonal shaping at the front and rear to support the lockup system.

Ambidextrous controls and wear-part design

The CAT4 incorporates several serviceable wear parts and ambidextrous features. A replaceable cam insert on the side of the upper, reminiscent of the SIG MCX, allows users to swap a known wear component. The ejection pad, forward assist, and charging handle pin are also designed to be replaceable as they wear, extending the rifle’s service life, though sourcing parts may be challenging initially for a new platform. The upper includes a shovel-shaped front to the handguard. The lower receiver draws inspiration from designs like the Griffin Armament Mark 1, with ambidextrous controls and a rounded, slightly wider bolt catch intended to be easy to find without snagging gear. The bolt catch resembles a maritime-style design and is praised for its usability.

Ambidextrous controls and ergonomics

Controls on the CAT4 pistol are fully ambidextrous. It has an ambidextrous 45-degree safety selector and an ambidextrous charging handle with a small shelf that may help redirect gas, aided by a channel along the side intended to vent gases away from the shooter’s face. The host notes that the charging handle and bolt catch are easy to locate by feel without looking. An ambidextrous magazine release is present on both sides of the lower, and a slightly flared magazine well helps guide magazines into place without being overly aggressive. The design aims to provide the upgrades many users typically add to a bare-bones rifle, integrated from the factory at this price point.

Hiperfire trigger, grip, brace, and initial impressions

The pistol uses a Hiperfire trigger described as a single-stage unit with a light, crisp pull and very short, tactile reset. The host demonstrates the trigger and comments on its quality, noting enthusiasm to run it more extensively. The castle nut is properly staked. The US Palm grip is thin, not overly bulky, and squared off at the front, which may not appeal to everyone but is easily replaced if desired. At the rear, the pistol uses a Magpul BTR-style brace with a QD sling attachment point and four adjustable positions. After roughly ten rounds fired for an initial segment, the pistol is reported to function reliably and not recoil excessively. The video closes with speculation about a potential future CAT5 in a .30-caliber configuration and an invitation for user reviews and questions as more in-depth testing is planned.