Response to "mike's review of faxon 16"" gunner - Faxon Firearms 5.56 NATO Gunner Rifle Barrel

interestingly I have a 20" gunner (.750 journal) and been working through incomplete cycling with 62g ammo going to the 430-500 angle, this I interpreted as UNDER gassed. Mike reported this on his 16" as OVER gas. but when I measured my port hole diameter I am well under the 0.093" spec, only getting a 5/64 bit into the hole (0.0781") vs a 3/32 bit which could be over (or at) spec at 0.0937". Apparently there are 6 ANSI drill sizes between the two bits, (#42 to 47) so some proper pin gauges are in order. I've always thought OVER gas ejected fwd, not back.

Presuming these barrels are all supposed to be spec, but it would be nice if the port hole diameters where included on the product specs and that ranges of these gas port sizes were offered by barrel manufactures.
common standard barrel port sizes
10.5" Carbine .073
11.5" Carbine .071
12.5" Carbine .068
14.5" Carbine .0625
16" Carbine .0625
13.7" Mid .0785
14.5” Mid .077
16" Mid .076
18" Rifle .0995
20" Rifle .093