Gas Port Diameter for 8" 300BLK?

[JeffWard]

It's been a few years since I shopped 300 BLK. I'm looking to build a second "pistol/SBR" upper with an 8" barrel.

Barrels I've seen have 0.072" gas ports... Too small for reliable subsonic? I seem to remember guys going closer to 0.094"??

Adjustable gas block or no?

What's optimal?

Thanks,
Jeff

[tfbit]

My 9" runs well with a 0.100" port, commercial BCG, and H2 buffer. Here's a nice link with info you may like:

http://micromoa.com/300-blk-port-size-testing/

[jrf]

http://micromoa.com/300-blk-port-size-testing/

I actually have one of their blocks(govna) with the plates. It's an interesting design that works if you only care to have 2/3 port sizes. I drilled out my plate accordingly for my 8.5" bbl that had a .100 port. So I have a large (actually made the barrel and hole in the plate 1.015) and small .076 hole on my plate. One for super and one for sub. Works great and is very easy to use.

Point being the .100 port works with the subsonic ammo I have shot through the gun WITHOUT a suppressor. So Yes I would say .072 is too small. Never thought to run the small port with subs at the range....I might have to give that at try next time out.