FEATURES
The B5 DPMS DR-10 complete lower receivers are functionally compatible with the PSA Gen1 and Gen2 upper receivers, however, we recommend matching to DPMS DR-10 or PSA Gen3 uppers for the best appearance and performance.  
The DP-10 platform does not share common design or mil-spec tolerances between manufacturers like the AR-15 platform. As a result, there can and will be subtle differences in the parts kits of various manufacturers. Some parts, like the fire control group, are shared with the AR-15 platform to preserve the options for upgrading. We recommend only using DPMS DR-10 or PSA PA10 parts with our uppers and lower receivers for the best results. We do not recommend using other manufacturers' parts in our products.