Nice looking barrel.  How fast do the 110g Barnes leave it?

Very nice and great to see more super short offerings. I'd love to see something like this in a 1:6 or 1:5 twist (ala Sig Rattler/Honey Badger) for the really heavy stuff.

sending PM

I have a 6" 300BO and it's a bitch trying to get it to cycle and still stay subsonic without a can on the end...now with a can, it's fine.  Also, this was with the Missouri Bullet coated 245gr and the palmetto 200gr.

The problem was that there was so little "dwell time" of the bullet in the bbl after the gas port bc the bbl was so short.  I drilled out the gas port with a 1/8" drill (0.125") which is bigger than this one at .105", and it still wasn't great great without a can (I didn't always like leading up my can, that's why I wasn't using it that often).  I found AA1680 to be best, and of course AA5744 just wasn't cutting it at all bc I couldn't fit enough powder in the case.  Btw, I put a wooden dowel in the bbl to prevent the drill bit from crashing into the other side of the bbl, and then a I took a brass bore brush to remove the lil bur that formed inside the bbl.  Had a lot of short stroking where it'd either fail to eject the case or it would eject the case but the bolt would not go back far enough to get behind the next round would fail to peel off the next round from the magazine...which really had me stumped as to what was going on at first.  I couldn't figure out why the brass would eject but a new round wouldn't be chambered.  Then I realized the case would eject before the bolt went back far enough to catch the next round.  I got the lighted buffer and buffer spring I could find, still no joy.

I'd like to know the suggested loads (powder, charge weight, and pill) for cycling subsonic loads in this bbl with this gas port size.  I'm happy that OP even posted the gas port size bc it shows they are at least thinking about what's important.  But I find it difficult to imagine this being able to cycle without a can on the end.

The other thing to remember is that muzzle pressure is always going to be somewhat high at 6" if there is enough pressure to cycle an AR action (around 10kpsi), which means that an aluminum form 1 suppressor may not be able to hold up to the muzzle pressure this short bbl would produce, whereas that same form 1 can would withstand the muzzle pressure of an 8.5" bbl.  At 8.5", the Pmuzz drops to around 5k-6kpsi or about the same as a 9mm pistol (well a little bit more).  Just food for thought.

..also I realize my cheapo gas block also could have been restricting gas flow, but I don't think that was the problem.

ETA - glad to see the twist, QPQ, and polygonal rifling. good stuff.  Mine was a 1:8" twist and I had no problems with stability at subsonic speeds...I have no idea why anyone would need anything faster than a 1:7".  But perhaps folks know better than me.

More ETA -- if you lighten up your carrier, you may be able to get better performance than I did, ironically i was just going thru my stuff and found the dern RTB cheap ass (but solid) lightweight carrier I ordered but never used, got a new project to test out.

Interested on this as well

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And...   ordered!  Now I have to figure out the rest of the build.  

No luck with subs and the Sandman K.  It looks cool though.

Interested, I'm looking to put together another short bufferless upper for my folding SBR lower.  Basically a Rattler with a forward charging handle.
This would be intended exclusively for supers (like the Barnes 110gr), unsuppressed.

Got my barrel in, searching around for 7", 1.5" ID handguards

These are a bit bigger than that, but I went w/ the keymod version of this for some of my ARs to put a suppressor under.

Exactly what I'm looking at.  Should have said >1.5", am also looking at Aero's enhanced gen 2 handguards, nearly the same with a few more weight-loss cuts and holes

https://aeroprecisionusa.com/ar15-enhanced-keymod-handguards.html

ordered the gen 2 7" from Aero

Sandman K and this barrel proved to be 100% reliable with supers today.

I bought it mainly for supers so I'm going to leave it alone.  The subs are not that quiet with the K anyway.

here was my day yesterday with this barrel and the v7 6.5".  cut and paste from another thread

velocity data: 70 deg F
barnes rangeAR 90gr
v7 2154, 2164, 2195, 2111, 2207
r2b 2116, 2070, 2110, 2116

barnes ttsx 110gr
v7 1975, 1961, 1972, 1978, 2001
r2b 1917, 1916, 1937, 1920, 1925

Federal copper 120gr
v7 1779, 1799, 1798, 1792, 1802
r2b 1735, 1739, 1723, 1732, 1748

fiocchi 220gr
v7 797, 798, 828, 806, 824 cycled unsuppressed, no lock back
r2b 838, 828, 849, 822, 838, did not cycle unsuppressed

60 day rule