Using a barrel built to a similar large specifications as the X-Bolt, the Browning AB3 packs large accuracy and characteristics into a brilliant price rate. The GAU-eighteen/A is a light-weight variant in the M2/M3 and is particularly used around the USAF's MH-53 Pave Very low and HH-60 Pave Hawk helicopters. https://browningfirearmstoreusa.com/