PMM Duty Compensator for FN 509

Compatibility

Modification required

Model

FN 509 Fullsize

Based on

Manufacturer documented

Based on manufacturer documentation or support information.

Requires a THREADED BARREL in 1/2x28. Most of these pistols do not ship with one — check your barrel before buying. NOT compatible: 509 Edge Series, 509 Compact MRD w/ Compensator, 509 Fullsize MRD, non-509 pistols. PMM allows other 1/2x28 barrels but warns the fit varies — "will work with others that have the same threads. (Gap may vary)" — which is a maker stating plainly that same pitch does not mean same shoulder standoff. Shim-and-timing, no set screws. Ammo guidance: best with +P or NATO spec; avoid Blazer 115, WWB 115, Armscor 115, PMC 115, and all reloads.

Check your exact model and part before ordering. Fitment limits