Yankee Hill 431524A Mini QD Flash Hider 5.56 NATO Black Phosphate 5/8"-24 Tpi Finish: Black Phosphate, Condition: New, 16% Off w/ Free Shipping

It will fit 30 cal. Just make sure it fits your suppressor.
Go to YHM's website to see.

Both the 4315 and 4302 series of YHM suppressor-adaptor muzzle devices are usable for both 5.56 and 7.62 (but not 9mm). The last two numerical digits of the part numbers just indicate the threads per inch, i.e.: -28A= 1/2x28 thread, common on 5mm rifles and pistols, -24A=5/8x24 thread, common for 300BO,7.62 Nato, 30-30, 300 Magnum. The -15A are for AKs, and the -36A are for IWI and some other euro guns. I run 30cal surpressors with YHM female adaptors on all my rifles, using both the -24 and -28 muzzle devices, depending upon what barrel threading the rifle has. I've found the YHM website significantly lacking for search features and proper product descriptions and details. Their lack of clarity on product applicability has likely resulted in Optics Planet's product manager for this line incorrectly listing this -24A part as "5.56". They should list it as "5/8x24, up to 7.62 diameter"...the same max safe diameter for all thread pitches of these two models.