How many of you would be interested in a 10.5" 300blk drop in (complete) barrel that is reliable for subs and supers?

BigDog, Faxon, Marvin, I haven't checked lately, are all of the parts being made 3rd party and/or are they available in limited qty from bushy?

Sure would love to see this get done!

To answer your question, both.

Marvin makes complete drop-in kits but doesn't do pistol gas conversions needed for the short 300blk barrels. I believe he got a 16" 300blk to function as you describe using his complete gas system (Carbine gas).

Dana aka Bigdog buys spares from BM/Remington and builds them up. To my knowledge he's the only one doing pistol gas builds. There's a lot involved in that you have to mill out the charging handle tray and also mill down the gas block. Take it from me, this is not easy to do with standard  tools.

I should mention, I had Dana build me a complete 10.5 300BLK barrel assembly using factory parts. I supplied the new barrel and my gas regulator, and I think that was it.

The issue with the 300 kits is the gas blocks are too large to fit under the charging handle tray.  Plus if that's not good enough, every barrel is different so there isn't an exact spec for the parts.  

I have the designs for a new gas block but I haven't had enough money to test it out yet.  The factory components work really good for the conversions.

That being said, 300 in a 10.5" is a great setup for the Acr.

Are factory components coming available at all any more??

I generally have enough on hand to build 2-3 barrels at any given time.  I have a business account with Remington so I can get parts by request.   They usually have everything in stock minus regulators.  The problem is they are expensive and charge tax for a normal order.