Rock River Arms (RRA) offers a selection of LR-308 upper receiver assemblies, designed for compatibility with their LAR-8 lower receivers. These uppers are chambered in .308 Winchester/7.62x51mm NATO and are available in various configurations to suit different shooting preferences. One notable model is the Predator HP Upper Half, featuring a 20" fluted stainless steel barrel with a 1:10 twist rate, bead-blasted and cryogenically treated for enhanced accuracy. It includes a low-profile gas block and a 17" RRA lightweight free-float M-LOK compatible handguard, providing ample space for accessory attachment. This upper comes equipped with the RRA Operator Brake and includes the bolt carrier group and charging handle assembly. Another option is the Mid-Length A4 Upper Half, which comes with a 16" chrome moly HBAR barrel, also with a 1:10 twist rate. It features an A2 flash hider and an 11" free-float handguard, offering a more compact setup suitable for versatile applications. It's important to note that RRA's .308 caliber upper halves are specifically designed for use with RRA LAR-8 lowers and may not be compatible with other manufacturers' lower receivers. For detailed specifications and compatibility information, consulting Rock River Arms' official website or authorized dealers is recommended.