Handy Kit for Building a Versatile, "Feature-Rich" AR-15 Upper Why settle for "basic," when you can build a new AR-15 that's MUCH more! Our handy AR-15 Upper Receiver Build Kit contains components you need to assemble a full-featured, high-performance AR-15 carbine upper half with the rugged, versatile Brownells Wrenchman™ handguard. The Wrenchman™ provides a rock-solid platform for mounting accessories, with a Picatinny top rail, rows of M-LOK slots all around, and QD sling swivel sockets. Even better, it's extremely EASY to install! Other premium-quality components in this kit include a Ballistic Advantage 16" carbine barrel set up for a mid-length gas tube to help ensure your new rifle cycles reliability (gas tube included, of course), a ZRO Delta mil-spec stripped M4-type upper receiver that's compatible with a vast array of aftermarket parts, and a Luth-AR upper small parts kit. Customize with the charging handle and bolt / carrier group of your choice to complete the upper assembly. Then, you'll need to start on the lower!