Ammunition identity and chamber markings
Why similar cartridge names, appearances, or magazine fit do not establish safe ammunition use.
Names are not interchangeable
The book devotes separate attention to .223 Remington and 5.56 NATO, then surveys other AR-pattern chamberings. The useful safety principle is that similar appearance or a shared platform name does not establish that ammunition is appropriate for a particular firearm.
OPEN FULL SIZE ↗An ammunition photograph from the book. Appearance alone does not establish chamber compatibility.
Source image: Real Avid, Top AR15 Mods, ©2021. PDF page 14.Read the firearm's own documentation
Use the exact chamber marking and the manufacturer's ammunition instructions. Do not infer ammunition compatibility from a magazine, a lower-receiver family marking, an online photograph, or another owner's rifle. If markings are missing, altered, or unclear, stop and obtain qualified identification before use.
Keep an old survey in perspective
The book's cartridge list is a historical survey, not a current availability guide or a conversion chart. DeadEye Syndicate does not carry forward its broad claim that most listed alternatives require handloading, or treat similar cartridge names as equivalent standards.
When ammunition identity or chambering is uncertain, do not use the firearm until the uncertainty is resolved.