If you can find one.
https://www.civiliantacticalweapons.com/wpctw/st-22/
https://www.thetruthaboutguns.com/gun-review-spikes-tactical-st-22-m4-carbine/
https://search.brave.com/search?q=s...summary=1&conversation=5a1ee212100f960e536203
Quote:
Spike's Tactical ST-22 is a dedicated .22 LR upper receiver designed for AR-15 platforms, offering a complete rifle solution or an upper that can be mounted on a compatible AR-15 lower receiver.2 The upper features a 16-inch barrel with a 1 twist rate, specifically designed for .22 LR ammunition, which is crucial for optimal accuracy and performance compared to conversion kits that adapt .223 barrels.23 The bolt system uses a Jonathan Arthur Ciener design, machined from heat-treated 4140 Chromoly steel with an NP3 Nickel Teflon finish, and is paired with a dedicated charging handle.23
The ST-22 is praised for its high build quality, reliability, and accuracy, with users reporting consistent performance and the ability to achieve tight groups at 25 yards.237 It is available as a complete rifle or as an upper only, with options for various barrel lengths, rail systems, and accessories like the Daniel Defense Rail system or Troy sights.3 The rifle uses Black Dog polymer magazines, which are recommended for reliability, and the design prevents fouling of the gas system compared to conversion kits.67
While the ST-22 is considered a top-tier product, it comes at a premium price, with complete rifles listed around $699 to $1,235 and uppers priced at approximately $868.23 Some users have reported initial reliability issues, such as feed and extraction problems, but these were often resolved through modifications like installing a high-speed hammer from J&P and having the rifle tuned by Spike's Tactical, which significantly improved performance.7 The company also offers support for existing kits, even if new production has ceased.7
The ST-22 can be used with a semi-automatic lower receiver, and while it is one of the few .22 LR uppers compatible with a full-auto lower (subject to NFA regulations), the specific complete rifle listed for sale is configured for semi-automatic fire only.2 The product is also available with a pistol plug, designed for use with self-contained BCG/Buffer assemblies, allowing the lower receiver to be plugged instead of using a buffer tube.