Alexander Arms UST17 Upper | 18″ Fluted Barrel | M-LOK

This Alexander Arms UST17 upper assembles as an AR-15 compatible upper with an 18″ fluted steel barrel and an M-LOK handguard for accessory mounting. The package includes an A2 flash hider, a parts kit for lower conversion, and two 10‑round magazines. The design emphasizes a lightweight upper for AR-15 platform builds and straightforward installation onto standard lowers.

Product Specifications

• The manufacturer is Alexander Arms.
• The model is listed as the UST17 upper.
• The barrel measures 18 inches.
• The barrel material is steel.
• The barrel is fluted and ships with an A2 flash hider.
• The muzzle threading is 1/2-28 RH.
• The handguard uses an M-LOK attachment system.
• The handguard finish is listed as black in the provided data.
• The upper operates with a blowback operating system.
• The package includes two 10‑round magazines.
• Includes a parts kit for lower conversion containing a recoil cassette, magazine well insert, and magazine catch.
• This upper is specified to fit standard AR-15 lowers.
• The item is cataloged as an AR-15 accessory in the source data.
• The provided package dimensions are 4.55 x 9.90 x 37.60 inches.
• The UPC for this product is 819511021295.

The UST17 upper combines a fluted 18″ steel barrel and M-LOK versatility to give builders a straightforward AR-15 upper that supports accessory mounting and simplified lower conversion. The included magazines and parts kit make this a convenient option for a dedicated upper build where a fluted barrel and M-LOK handguard are desired.