This AR57 Upper is constructed with a steel barrel, muzzle brake, bolt carrier group, buffer, and screws, all built into an alloy monobloc receiver. The sight system is a 13 slot Picatinny over the operating handle, with 3-slot upper and lower forward rails.

The AR57 ULT Complete Upper Assembly, chambered in 5.7x28mm with a 12" lightweight barrel and M-LOK rails transforms any AR-15 lower into a 5.7x28 firearm. Featuring a unique top-loading design that ejects downward through the AR-15 mag well, this lightweight upper features a stronger, lighter rail with a melonite black coating.

5 天之前 · These AR57 parts will let you start a 5.7 build, capitalizing on the AR platform while using the amazing 5.7 cartridge. These FN 5.7 x28 AR parts let you build a pistol, a carbine or an SBR with the appropriate tax stamp.

AR57冲锋枪的上机匣组件也有3种不同的型号可供选择，分别为标准型、SBR型和6英寸型，这3种上机匣组件要求配用的枪管长度不同：标准型上机匣组件组合的是长406mm的枪管，枪管从上机匣延伸得比较长，枪口前方切削有螺纹，可加装多孔型 消焰器 ；SBR型上机匣 ...

5.7x28 AR Uppers are chambered in the small yet potent round. Now available in the AR 5.7 rifle platform with proprietary magazines.

Experience the ballistic performance of the iconic FN P90 in the familiar AR-15 platform with a 5.7x28 upper receiver from Classic Firearms. Whether you're looking for a rifle or pistol upper, we've got just what you need to complete your dedicated AR57 build for sale. Buy your next AR57 5.7x28 complete upper receiver online at Classic Firearms!

Convert your AR-15 type rifle to shoot the same 5.7x28 ammo as the legendary FN P-90 PDW! This AR57 Upper is constructed with a steel barrel, muzzle brake, bolt carrier group, buffer, and screws, all built into an alloy monobloc receiver. In other words, it is ready to drop in and push pin. It is also built as solid as a tank.

2008年11月30日 · The AR Five Seven is a one piece 5.7×28mm upper that attaches to a AR-15 lower and uses the 50 round FN P90 magazines. 57 Center posted a few photos of their new SBR suppressed submachine gun/PDW: How cool is that! UPDATE: After writing a three paragraphs about integrally suppressed firearms it turns out this is not integrally suppressed!

This revolutionary design allows the use of 5.7x28mm ammunition on the AR15/M16 Platform. Simply attaches to AR15/M16 type Rifle/Pistol lower halves like any standard upper. Ejects through magazine well. Accepts PS90 magazines (up to 50rds!). Includes buffer. Complete assembly with "SBR/Pistol" 11" Barrel, Flash Suppressor, Bolt and "Carbine ...