1/2-28 vs 5/8-24: A Thread Pitch Guide

Thread pitch is the size and spacing of the threads on your barrel. Your muzzle device has to match it exactly.

• 1/2-28 is the common thread on 5.56/.223 AR-15s and many 9mm barrels.
• 5/8-24 is the common thread on .308, 6.5 Creedmoor, and larger rifle barrels.

Those are conventions, not rules. Always check your barrel's spec or ask the manufacturer.

Every LPM flash hider and brake comes in both

Pick the one that matches your barrel. Bore matters too: our Eclipse and Liberty Bell have a .30 cal bore, which suits 5.56 through .30 caliber. The Baby Bell has a .395" bore for 9mm and smaller.

Mixing pitches

Want to run a 5/8-24 device or silencer on a 1/2-28 barrel? Our 1/2-28 to 5/8-24 Thread Adapter adds only .19" and has a 3/4" hex for a standard armorer's wrench.

Direct thread silencers

Direct thread silencers use a Rearden Ti Direct Thread Adapter, also in 1/2-28 or 5/8-24. Order the one that matches your barrel.