Layout D - Upper Authority

Layout D (comb with C + load more)

Side-by-side comparison diagram of two rifle operating systems showing gas flow in a direct impingement system and a piston-operated system

Direct Impingement vs Piston AR: Key Differences and...

Bolt carrier group partially extended from an AR-15 upper receiver showing bolt lugs and cam pin on a workbench

AR-15 Cycle of Operations: How the Rifle Functions...

Disassembled AR-15 components arranged on a workbench, including upper receiver, lower receiver, bolt carrier group, and buffer system

AR Platform Fundamentals: How the System Works

AR-15 bolt carrier group with bolt extended next to a barrel extension on a workbench

AR-15 Headspace Explained: What It Is and Why It...

Close-up of an AR-15 upper receiver on a workbench with the gas block, gas tube, and partially removed bolt carrier group visible.

AR-15 Dwell Time Explained: How It Affects Cycling and...

AR-15 bolt carrier group on a dark workbench showing bolt lugs and carrier body

Bolt Locking and Unlocking Process Explained