I have a Rainier Arms forged receiver set (made by Mega/Zev) that looks and fits perfectly. I planned on using it for a customized M4gery build (14.5 Socom FSB with MI drop in). Unfortunately, the finish on the receivers isn't the typical anodized look, it's quite shiny and doesn't match the full look of the barrel and handguard. Looks odd.

Is there any way of possibly dulling the Rainier receiver finish without cerakote or paint, or risking the integrity of the finish? Or vice versa... Maybe matching the shine for the handguard?

Fine Scotch Brite pad?  I've used them to restore the satin finish on a stainless revolver, never tried them on an anodized finish.

I wish there was a "milspec" receiver company that actually makes perfect fitting receivers. I can't stand a bunch of slop and gap especially on something that's going to last me a long time. Not looking for a "Gucci gun" build, but something that's not a raggedy mess. Aero and Anderson have both let me down so far, that's why I bought the Rainier/Mega/Zev receivers. Just wished they'd use standard anodizing.