This BCA AR-15 complete .17 hmr rifle length upper has a 16" heavy barrel with a parkerized finish and features a 1:9 twist rate. It includes a 15" MLOK rail, a M4 flat-top billet upper receiver, a BCA bolt carrier group, a flash hider, and a right-side charging (Gen2) handle (patent protected). This upper is compatible with any mil-spec AR-15 lower with an unnotched hammer (rounded) and this upper includes the buffer spring and buffer. (Our included buffer and spring are for a carbine style, adjustable stock)Shop more .17 hmr uppers here!Magazine not included. 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"}}