US Palm Storm CAT4: Billet AR-15 Rifle and Pistol at $1,399

US Palm built its reputation on AK accessories: pistol grips, magazines, and soft goods for Kalashnikov-pattern rifles. The brand is part of the Century Arms family, the same operation behind some of the most widely distributed AK imports in the United States. Entering the AR-15 market in 2026 is a deliberate pivot, and the Storm CAT4 is the first product off that line.

The CAT4 is not a rebadged Century Arms lower with mil-spec parts. US Palm describes it as a ground-up development effort engineered in West Palm Beach, Florida. The platform takes its name from the hurricane category scale, with higher numbers indicating more capable configurations. The STORM CAT4 leads the lineup at launch.

The timing is deliberate. Century Arms and US Palm are betting that the mid-tier duty AR market, the $1,200-$1,600 range where premium features typically start appearing, has room for a new entrant with billet receivers, a premium trigger, and full ambi controls already in the box. The AR-15 market in 2026 is competitive, but brands that can differentiate on factory features without a price penalty are still finding buyers.

The CAT4 is a direct-impingement, gas-operated 5.56 NATO AR-15. The upper and lower receivers are machined from billet 7075-T6 aluminum with a Type III hardcoat anodized finish. The upper receiver houses a user-serviceable hardened steel case deflector and forward assist housing, a meaningful detail because steel wear points outlast aluminum in high-round-count applications. The lower carries an integrated trigger guard and a flared magwell that helps funnel fast reloads.

Barrels are cold hammer forged from 4150 chrome moly steel with a 1:7-inch twist and nitride finish. The 1:7 twist stabilizes projectiles from 55-grain to 77-grain, giving the rifle genuine utility across the range of common 5.56 loads. Both the bolt and barrel extension receive a DLC (Diamond-Like Carbon) coating, which reduces friction and resists corrosion more aggressively than standard nickel boron or phosphate treatments at this price tier.

The Hiperfire EDT Designated Marksman trigger is a single-stage design that tested at approximately 3 lbs 4 oz in Guns and Ammo testing. The EDT line is aimed at precision and duty applications where a lighter, crisper break improves accuracy without sacrificing the reset characteristics needed for rapid fire. At most retailers, the EDT runs $90 to $130 as an aftermarket purchase; it ships standard on the CAT4.

Every control on the CAT4 is bilateral. The bolt catch and magazine release are mirrored on both sides of the lower, and the safety selector operates with a 45-degree throw, shorter than the standard 90-degree, which reduces the distance a thumb must travel to reach the fire position. These features typically cost $80 to $150 in aftermarket parts on a standard AR build. On the CAT4 they come from the factory.

The US Palm Reduced Angle pistol grip is an in-house design that positions the hand at a different angle than a standard A2 grip, intended to improve trigger finger alignment and reduce wrist fatigue during extended strings. The charging handle is also a US Palm proprietary design, replacing the standard commercial latch with an ambidextrous version integrated into the charging handle body.

The Mono-Loc handguard uses a proprietary barrel nut and extension to connect the free-float tube directly to the upper receiver. The result is a continuous Picatinny top rail from the receiver to the end of the handguard, uninterrupted by the joint that creates small gaps in some designs. The seven-sided aluminum tube provides M-LOK slots on five faces. For a deeper look at how free-float handguard systems compare, see our handguard selection guide.

The standard muzzle device on both the rifle and pistol is the US Palm Hurricane Hybrid Flash Hider. The three-pronged design with a twisted profile is engineered for two functions: flash suppression and recoil control. The prongs are oriented to direct combustion gases upward and to the sides, reducing muzzle rise without the lateral blast signature of a standard compensator. The thread pitch is 1/2x28, which is suppressor-compatible and accepts most standard flash hider-style suppressor mounts.

The Hurricane unscrews like any standard muzzle device. Shooters who want to run a different compensator, a 3-lug mount, or a direct-thread suppressor can replace it without special tooling. For a full breakdown of muzzle device options for AR-15s, our muzzle device guide covers the trade-offs between flash hiders, compensators, and suppressors.

Alongside the CAT4, US Palm introduced four suppressors under the EOS (Eye of the Storm) designation. All four use 3D-printed additive manufacturing from 718 Inconel, except the EOS-30Ti which uses titanium. This construction method allows internal baffle geometries that are impossible to machine conventionally, and 718 Inconel offers corrosion resistance and heat tolerance well above stainless steel.

The EOS-556 targets 5.56 NATO gas-operated rifles. At 12.5 oz and 5.5 inches, it sits in the K-length suppressor category, short enough to keep the rifle balanced while delivering meaningful sound reduction. The 1/2x28 thread pitch mates directly to the CAT4's factory thread. A titanium direct-thread mount is included. HUB (Host Use Blend) compatibility means the EOS-556 can also run on a QD mount system if the shooter prefers a no-tool attach and detach solution.

The EOS-AK fills a gap in the market. AK-specific suppressors with 14x1 left-hand threads have fewer options than 5.56 and .30-caliber AR cans. US Palm's AK roots make this a natural extension of the product line. The EOS-30 handles 7.62 gas guns, and the EOS-30Ti is optimized for subsonic .300 Blackout, where titanium's lighter weight matters for a suppressor that will live on the muzzle most of the time.

MSRP is $899.99 for the EOS-AK, EOS-556, and EOS-30. The EOS-30Ti runs $999.99. Under the One Big Beautiful Bill Act effective January 1, 2026, the NFA transfer tax on suppressors is $0. The ATF eForm 4 approval process still applies, but current median approval times are running approximately six days. For more on the buying process, see our suppressor buying guide. The broader suppressor market context is covered in our 2026 suppressor boom coverage.

The $1,399 price point lands the CAT4 between the budget mil-spec tier (PSA PA-15 at $499-$699) and the established mid-tier brands (BCM Recce at $1,400-$1,600, Aero M4E1 Enhanced at $900-$1,100 assembled). The CAT4 makes its case on factory specification rather than brand recognition.

The direct comparison that matters most is what the CAT4 costs versus building a comparable AR from scratch. A billet receiver set, a cold hammer forged barrel with DLC BCG, a Hiperfire EDT trigger, an ambidextrous safety, ambi bolt catch, and a quality free-float handguard totals well above $1,399 as individual purchases. The CAT4 is essentially that build assembled at a cost-of-goods advantage from Century Arms' manufacturing scale.

Brand skeptics will note that Century Arms is better known for budget AK imports than premium AR builds. That concern is legitimate, but the CAT4 is a ground-up West Palm Beach design with documented premium components rather than a rebadged production rifle. Independent testing by Guns and Ammo measured the trigger at 3 lbs 4 oz and found function satisfactory. The real test will come with higher round-count evaluations and third-party accuracy testing.

For shooters configuring a suppressed rifle build, the CAT4's threaded 1/2x28 barrel and a companion EOS-556 create a complete suppressed system from a single brand at $2,299. That package competes with separately sourced mid-tier ARs plus mid-tier suppressors. Use our AR-15 builder to compare suppressed rifle configurations and see how the CAT4 package stacks up against other build options at this budget.

The Storm CAT4 rifle and pistol are both in stock now through the Century Arms dealer network, including Davidson's Guns, and directly from store.centuryarms.com. The EOS suppressor line is also available through dealers and direct. Both the rifle and pistol configurations carry the same $1,399.99 MSRP. The two finish options are all-black and Storm Green, with the same pricing for both colors.

The pistol configuration is an NFA item when registered as a short-barreled rifle; when used with the included Magpul BTR stabilizing brace, it can be owned as a pistol under current federal law. As of January 1, 2026, the NFA transfer tax is $0 under the One Big Beautiful Bill Act, making the SBR registration path significantly more accessible for shooters who prefer a registered SBR to the brace route.

US Palm's move into AR-15s is the most ambitious product launch from the Century Arms family in years. The spec sheet is aggressive for $1,399: billet receivers, CHF DLC barrel, Hiperfire EDT trigger, ambi controls, and a free-float handguard. On paper this is a legitimate $1,800-2,000 build at a $1,399 price tag.

The unknown is durability under hard use. Century Arms does not have a track record building ARs at this specification level. The CAT4's factory features are verifiable, but the assembly quality, gas system tuning, and long-term reliability under suppressed fire will require extended field testing beyond launch coverage. Guns and Ammo's initial function testing was positive, but a single function test does not answer the 10,000-round question.

At $1,399 with these specifications, the CAT4 puts pressure on established names in this tier. If US Palm can demonstrate reliability parity with BCM and Aero at this price point, it becomes a strong recommendation for the suppressed duty rifle category. Until that independent testing exists, it earns a "watch this" designation: strong specifications, unproven long-term track record.