Does it allow the gas system to operate properly?
If so, no worries...and if not, it won't be hard to fix.
Remove the gas rings and snap the micrometer onto the gas ring area of the two bolts. If they match, check the 'tail' of the bolt for size.
Then use corborundum cloth in a pair of pliers to turn that area down to the proper size, and finish by cleaning it well, then reinstall the gas rings.
And if you screw something up, well, it was already broken, correct?!
Stop making stuff up, Tweak. I've never had an out-of-spec part from DPMS.
not the end of the world.
Check the bolt at the fliar at the gas section. If you find a un-milled lip just before the flair, then chuck the bolt up in a drill and spin file the high line off to correct the gas section of the bolt.
Bottom line is to just mic the bolt and see where it is too large and correct.
Or, You could just piss and moan about the item not working and post here, instead of getting DPMS on the phone and have them send you a replacement part (Oh wait, you already did that).