All the discussion about GP sizes got me thinking, is there a recommended GP size for a 11.5" 5.56mm barrel with carbine gas system and carbine receiver extension and buffer, if the user wants to run suppressed AND unsuppressed, without resorting to AGB/ABC, or the Vltor A5 system? We have a numerous Colt 6933's, and I have tested one with a GT halo, and that gun runs 100% both ways and has around 750 rounds through it. Mostly PMC 55 grn fmj, with some Hornady 55 grn fmj, and about 100 rounds of 55 grn Gold Dot. Sample of 1, though, not a long term test, only the 1 can, etc. I have no hard data on the size of the Colt6933, GP but have seen reports varying from .069" to .093". I have read of more than a few folks using BCM 11.5 barrels suppressed and unsuppressed and having no problems. And there are many reports of the BCM 11.5 using a GP of .076". I understand that you are better off to set the rifle up to run optimally as dedicated for 1 condition OR the other, not both. As in, for a dedicated suppressed 11.5, the GP should be around same as a 16" carbine, with a .062" GP. Caveats: ammo: Speer Gold Dot .223 55, 62, 75 grn for duy, but also quality FMJ .223 and 5.56 for practice Buffer: can vary but let's say H buffer as a baseline Can: let's say full size like the Halo, M4-2000, Saker, or even a somewhat shorter can like a Sandman-k, or a Mini-4. Your thoughts?