I dont see a point as IMO its not needed. 300BLK was designed to not need adjustable gas as Mr. Silvers points out repeatedly.
16" .223 runs AWESOME with an H buffer. If its over gassed(like a S&W or something like that) than an H2 will generally get you rolling perfectly. No need for adjustable gas IMO. This is proven time and time again that the guns run with either of these two buffers.
9" 300BLK runs AWESOME with an H buffer as well. The recommended is an H2, but an H runs like a raped ape. The H2 will be SLIGHTLY quieter. Ive probably run 3k+ on an H and probably 2k+ on an H2. No appreciable difference in how the gun runs really(im running 99% subsonic 300BLK). Im sure somebody with more high tech equipment than me could prove the gun runs better(cyclic rate) or is quieter(DB reduction from the can) or whatever. If I was running more supers than subs, the H buffer MAY have run to fast, I dont know, dont have enough experience running supers. Most 300BLK barrels in my experience are WAY under gassed and an adjustable block wont help you out at all and running an H2 buffer in those will cause nothing but issues.
I run an adjustable on an 18" SPR because I am using JP low mass carrier and silent capture spring. You NEED adjustable gas to tune that system. But with either 16" carbine 5.56 or 9" 300BLK an H buffer will run either and run it reliably. Now if you were talking needing a C buffer in the 5.56 gun and an H2 in the 300BLK, THEN I would consider saying "get adjustable gas to tune", but with an H running happily in either(in MOST guns), I would tend to leave it be and just rock the H. If the 16" 5.56 would run well with an H2, again, run it and leave it be. I tend to err on the side of simplicity and adjustable gas adds a level of complexity that if I dont personally NEED it(as in the case that my SPR needs it) I would rather tune with a buffer or spring. I also tend to never run low powered Wolf, im either running XM193 or im running fairly hot M193 clone reloads so I dont ever feel in my carbine gas guns I need a C buffer to get it to run right. I actually run the H2 with my 9" 300BLK and my 10.5" 5.56 runs like a raped ape with it as well so I just roll with it. So in some people's setups or ammo they run, an adjustable gas with a C buffer might be the way to roll, but me personally, and I also believe in the OP's case(since he doesnt seem to know a ton of the technical in's and out's) simpler is better so I would still say in his case just running an H buffer for both uppers would be the way to go. It all though in the end comes down to the overall setup of the gun and the ammo being shot. A properly drilled 16" .223 gun runs great on an H buffer. A properly drilled 9" 300BLK gun will run awesome on an H buffer(even though the recommended is an H2). So if I only had 1 buffer to choose, it would be an H.
BUT it seems as this discussion is purely academic as the OP's has decided he doesnt want to stay and learn about the systems and just wants to go away.
