This BCA AR-15 complete 9MM pistol length upper has a 5" M4 barrel with a parkerized finish, and features a 1:10 twist rate, with a blow back gas system. It includes a 4" MLOK rail, an M4 flat-top billet upper receiver, a BCA bolt carrier group, a flash hider, and Gen 2 (patent pending) Side Charging handle and fits on a mil-spec AR-9 lower. Shop more 9mm! Check out Magazines here! {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="56"}} {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="98"}} {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="91"}} {{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}}