You might check out Faxon barrels ,Ballistics Advantage aka Aero Precision , Lija , Krieger , Bartlein, Proof Research , Schneider.
Are You building an A1 ,A2 , M4 ?. I just scanned through the posts this evening and saw your post .
I'm finalizing MY LAST AR build . I had parts pieces extra parts stock and found a Deal on a NICE barrel and figured I'd pop together a decent lower ,from MY parts and pieces to complete this last Rifle .
So bought a Quality upper receiver and squared it up and assembled it . Along with an extra quality lower I had triggers pins springs the whole Nine yards . What I was short of all things was a stock and Magpul grips . ALL MY AR 15's and 10's wear A2 stocks ,as I'm 6-4 that 5/8" helps but isn't why ,availability is . I detest those plastic shoe horn skeleton stock abominations .
IF YOU are NOT going for super accurate ,I'd NOT spend big bucks on a high dollar barrel . IMO NOT worth it and here's why .
I've got a couple of Older Bushmasters pre 98 XM15-E2S 20" Target chrome lined bores ,along with targets proving in MY Rifle anyway ,that #15 shots can fit under a dime at 200 yd. . Yeah STOCK out of the Box AR's . BL C-2 25.5 gr. with Bulk 55 grain bullets
I'm sure I don't have to tell anyone who is building AR's what they cost NOW . Do I like the other AR's I've built ?, OH Hell yes are all of them as accurate as those original Bushmasters , OH HELL NO . They Look cool though
. I enjoyed building ( assembling ) AR's regardless of calibers chosen and Most Proud of MY last 6.5 Creedmoor and it too wears A2 furniture
. It's well past time I SHOOT ALL OF THEM and Quit building them . That's on ME .