There are several major makers of the 300 Blackout in the AR platform.  I know each will have its own champions, but is there any consensus among the owners on which are considered the best and which have known issues?

Tag for info..   I'm not sure if I want to just buy a complete upper of piecing one together.  Headed to the gun show in the AM to pick up a stripped lower.
 

I want the info as well.


I have been looking at DDM4V5 300 Blackout upper and I'm sure it would be fantastic (I have a DDM4V5) but it is costly...

By no means an expert here. I wanted a rifle with a primary purpose of running as quite as possible in my budget.  I chose to build mine. Using a YHM upper and BCG initially I used a CMMG barrel with a carbine length gas system..  I had a few problems running subs with out the can. So I switched to a Grim Reaper Tactical with a pistol length gas system.  With the can in place it is not much louder than my tac sol Ar22 with my Halo on it.

I built my own using a PSA 16" carbine barrel, and Rainer Arms upper receiver. No problems!!

I own various 300 BLK rifles and uppers (a total of 5 at this time; another on order).  My most accurate one is my DDM4V5 in 300 BLK.  My 2nd best is my Delta Company Arms upper (but I think they are essentially out of business now).  3rd best is my Core15 upper.  Note:  even my "worst" still shoots fine for me.  My "worst" took 2 deer, each with one shot last season.  For this season I'm going to try my DDM4V5.  In the case of the Daniel Defense, I bought the complete rifle.  I did change out the trigger for a smoother, lighter pull.  

A friend just put his upper together with a CMMG bbl.  Initial shots fired yesterday show it should be nicely accurate.  He did bore scope the bbl and commented how smooth the rifling looked.  The only negative he found was that it wouldn't properly function his AR with light frangible bullet loads that function 100% in his Model 1 Sales upper.  Jacketed bullet loads all functioned properly.  We did not try subsonic loads in it, as he doesn't own nor intend to own a suppressor.  The light frangible loads wouldn't function my DDM4V5 either.  My subsonic 220gr loads function 100% in the DDM4V5 without a suppressor.  

Any one heard of the uppers made by redline firearms?