About a year ago I made my entry to the 6.5 Grendel with a Bear Creek Arsenal upper (type 2 with 18" barrel). The rifle shoots fairly well but I can't say I am completely happy. I have fired just over 400 rounds through it, so it is as good as it's going to get.
My concerns:
1. The gun will shoot 3 of five shots (not necessarily 3 in a row)  into a very tight group, but there is always two shots that go wide. The lower has a Geissele trigger in it and while I am not the worlds best precision shooter, I have been at this a while and this is not a problem I have with my other long range guns.
2. When I shoot the gun fresh off of cleaning the barrel it groups fairly well as stated above, but the groups widen with each group and within 15 rounds the gun is shooting 2 inches. Once cleaned the gun returns to it's roughly MOA accuracy.

My Questions:
1. Am I asking to much? Is it going to be worth putting a new barrel on? See picture for what I would call typical "clean Barrel" accuracy. I would like to get all five shots into .75"
2. I would like to stay with a 18 inch 1 in 8 twist barrel and have been considering / leaning towards either Odin works or Ballistic Advantage units as they are within my price range of $300-$400. Does anybody have experience with these makes of barrel? will they get to the .75 inch mark that I am hoping for?

Afterthought- I use the rifle for semi long distance (400-800 yard) steel and paper punching, but it is also a small deer and antelope rifle, so not looking to do the super heavy barrel thing.

Edit- Not sure why my pic isn't coming through

I would get a Faxon or Odin barrel

Looks to me like you're getting better-than-budget results out of a budget barrel.  Gonna have to pay to play if you want 1/2 MOA.

budget barrel, budget results.

try a criterion.

for $300-$400 get the criterion, dont go from one cheap budget barrel to a more expensive budget barrel.

I'm inclined to agree.  For the cost of that barrel, it seems to be performing very well.  Head over to 65grendel.com if you want to see what they recommend.

Is it possible that your technique is causing the fliers?  Parallax or some inconsistency?

A possibility, I don't see it in groupings with my other rifles though.

Son #1 just built his BCA 6.5G complete upper, with a YHM Melonited  20" Bbl. x39mm Cal. also in the works, he plans to
get them tested in a few weeks at the range (100 Yards)...

He has a brand new 20" HA 6.5G 4150 CMV Bbl. in Melonite finish as well as a back up Bbl. in case the BCA Bbl. does not
play nice.

We will see how they work out...

Damn nice shooting.

A few months ago I first got into criterion barrels and foe the price they can't be beat. Idk why someone would choose an "expensive budget barrel" like BA over a criterion for the same price.

Another option which get very good reviews are Lilja where many barrels are in stock and ready to ship.   Another great option is JP inc 18” 6.5 Grendel.   Noveseke, Wilson Combat just recently released 6.5 Grendel barrels and the LaRue Ultimate Upper are getting good reviews.

http://riflebarrels.com/shop/drop-in-barrels/6-5-grendel-ar319/