I'm converting a pre-existing upper of mine to .300 blackout and have a 16" pistol length barrel picked out, but cannot seem to find a matching gas block with the .093 port hole size. All gas blocks I'm finding seem to max out at .073ish. I'd like to insure it shoots both super and subsonic loads without issue so I'd like to ask someone with more experience if this would be an issue? If the barrel port is larger, but the gas block covers a percentage wouldn't that create an issue with pressure back feeding or halting at the block?

The port size on your barrel is what matters.  Unless for some reason the gas block is severely undersized.  I believe the standard hole size on a gas block is .125" I'd have to look at my print to confirm.

I have never seen a gas block with a hole that small. I think most of the ones I have installed have had the hole around 0.125".

....or even larger.  As stated above, the gas port in the barrel is the most important.  Gas block passages are generally much larger than any gas port you will encounter.  My 300 blk is a mid length gas system and its gas port is 0.120".  A pistol gas port will be smaller than that.

what brand of barrel? thats a lot of port for a 16" pipe.

ours are Ø.141" full open

Which ones are those?

I'll IM you, otherwise I might get dinged for advertising





We originally had our thru hole at 11/64ths but after doing some research we found that most barrels only needed an opening equivalent to Ø.082" to function. Testing was done on standard 16" barrels firing 5.56


Obviously the diameter had to change the the shorter the barrel, the shorter the distance between the gas port and muzzle, and the larger Ø/lower pressure the cartridge, but we never had anything require a hole larger than about Ø.130"
 

It does no good to have a barrel gas port that is larger than any other passage in the rifles gas system. Most gas tubes have an ID of 0.113 to 0.120.  In some cases the ID of the Gas tube becomes the new fixed restriction regardless of how big the gas port is.  The gas tube ID has to be larger than the gas port to eliminate this restriction.