Ahhh....I'm in the middle of spec'ing an SPR/DMR type build. Since I don't knock doors down, I'm using a 2-8x BDC optic and a 20" barrel with a muzzle brake.

So far, my specs are:
Magpul PRS stock
Spikes lower
Armalite LPK with RRA NM trigger
BAD lever
Spikes Upper
ADM QR mount
Nikon 2-8x Monarch 3 BDC
20" rifle gas high quality SS barrel; 1:7.5-1:8 twist; SPR type profile; threaded end; matched to bolt
Miculek or Precision Armament M4 72 comp
Adjustable low pro clamp on gas block
Midwest 3GML 15" forearm??

So, as you can see the barrel is not clear at all. I want an 18" or 20" SS SPR contour barrel that will put 10 shots into 2.5" at 300 yds or 10 shots into .75" at 100 yds. This is probably a .5-.6" 5 shot group. Also, would like to see xm193 under 1.5" at 100. I'm willing to work hard on a load to hit those targets, but would really like to keep the barrel under $400 and would like to wait under 3 months. I see my choices as:

WOA - $275
WOA - Shilen - $450ish
Shilen@ Midway - $$450 headspaced to included BPL
Proof Research@ Midway - $370
WOP - custom - $450-500
CLE - custom- $450-500

Custom means Kreiger blank, 223 Wylde chamber, 20" SPR contour, threaded end, rifle gas, M4 feed ramps, headspaced to my BCM bolt.

The question is how much compromise will going to the WOA std SPR barrel be? Tons of great reviews on it. I have a hard time believing that it will not hit or be very close to my target groups. So, based on your experience, what will I get for $200 more?

XM193 won't stay 1.5 MOA or under. I recommend a heavier buffer and/or stiffer magazine springs to compliment the BAD lever.

Probably up to 0.25 MOA better and longer X-ring life (~3000 vs ~5000).

If you're looking for legit .75 ten shot groups, you better spend top dollar. Even then you might not get that.

.75 moa ten shot groups is serious target rifle territory. You have a lot of equipment in your list that is not ideal for serious precision work.

I have a WOA varmint barrel that regularly shoots sub .7 moa five shot groups, but I wouldn't expect that kind of performance with 10 shots.

I also have one of their DMR barrels that runs about 1.2 moa for seven shot groups, but it is new, and I'm still working on loads. I expect it to get better. It is very consistent, however, and performs very well in the practical competitions that I bought it for. It has been interesting seeing the difference between shooting small groups at a bench and hitting targets in field conditions. What is good at one might not be good at the other.

You will not get 1.5 moa out of m193 with any barrel, no matter what anybody says. The ammo is not capable of it.

Absolute truth.  Well said.  I have a $500 Lilja match barrel.  416 stainless, 1:8, Wylde, Recon profile (heavy under the handguard).  It will shoot sub 1/2 MOA with my carefully laddered match handloads with Berger bullets in Lapua Match cases and individually weighed powder charges.  It shoots M193 and M855 no better than any cheap rack gun.  That ammo is 2 MOA or worse from any barrel.  Good barrels will not make it shoot better.

I get it XM193 was a stretch!

Novekse has an 18" SPR barrel that will get you near that level for under $450.  Probably closer to $400 if you look around.
I think Molon shot a sub .75 MOA 10-round group out of one (might have been best, not average).

You are off in imaginary land friend. Come back to reality. Buy the best barrel you can afford.

Get a Larue LT158 over an ADM mount if you want QD. Get a scope with more than 8x. Hell, get a 3-15x44 PST Gen II if you want .75" groups at 100. Only shoot Sierra match bullets or Bergers. Only shoot handloaded ammo. Only shoot Lapua or Nosler brass.

For God's sake... don't get a cheap ass RRA piece of crap. Get a Geissele 2 stage enhanced.

The Magpul PRS is not needed. Your priorities on the build are all ass backwards.

Cheap barrel, cheap ammo, cheap mount, cheap scope,  but probably the most accurate rifle of anyone you know... get real.

My Ruger RPR is shockingly accurate. 9 out if 10 people say it's the most accurate rifle they have every shot. It sports a 5-25X scope. The cheapest bullet I shoot through it is an ELD-M.

But you want an equally accurate rifle in an AR15 platform, using sub par parts instead of the best you can find. Most SPR don't shoot .75" groups. If they do its the best group of the day. You want .5" groups and put ANY limits on price you are crazy. I mean you need to see a shrink crazy.

I know somone with a Lilja custom .308 Remington 700 with blueprinted action etc. It does what my Ruger does... about .75 MOA 5 shot groups very consistently. But that's not good enough for your budget AR build you want to shoot circles around the bolt guns.

So get a Krieger, a JP Ultramatch, or other super high end barrel. I would not even get a Shilen, Lilja, or Noveske, I'd look at more than that, beause that is what you need to reach your goal.

Get a billet upper. Use a Chargemaster at the minimum and load to the same .1 grain on everyload.

I always love some good opinion...

I have upgraded the build to a Geissele High Speed. I own the RRA trigger and it is probably better than 90% of the ooooh look at my expensive AR triggers that I have tried. Yes, Geissele included and CLE.

ADM mount is a done deal. I owned a Larue. Both are good. I prefer the ADM.

I have a 2-8x with a BDC. Pretty close to optimal for large targets, but I would like 12-20x for smaller 600+ yd targets.. I could see going to a 2-12x or possibly bigger. I cannot see a huge scope on a 5.56, because the wind kills you past 600 yds with mag length ammo.

You do a great job of complaining about things like the PRS stock....What would you suggest to balance the 3lb 20" barrel and get lop/cheek weld perfectly adjusted?

You lambast me on my accuracy target, because some guys Rem don't shoot. My stock Savage 300WSM hits this at 100 yds. Is it the shooter. Good AR's can shoot!

I bought the barrel based on my barrel maker's experience. I had a Kreiger. Good barrel. Don't you get this is a gas gun? There are diminishing returns on all choices. It is worse on a gas gun. An AR will never really shoot a Kreiger to its potential.

Shilen wins benchrest competitions. Lilja too. Quit it. No esker does not! Cannot! JP cannot either. Good gas gun barrel, but not a winner. Lol!

Bolt guns built right shoot 0.25 MOA at 100, if the shooter can. Some shoot 0.1 MOA.

Do you shoot AR's? Or just post about them on the internet.

.75 MOA is not amazing. It is a rock solid bolt gun....slightly better than that in a gas gun.

You could get a UBR and a Stealth weight.

Update....still getting this thing going....last group was .89 MOA at 100 yds for 5 shots...Load needs work. Better than my XM193 matched ballistics reload! That thing shoots like a house on fire in my carbine....but 2” at 100 yds in this....WTF?!

The groups from my Lilja AR barrel are down in the .4s, but it takes more than barrel.  I can't do that with off the shelf match ammo.  Maybe .6s.  To get lower, I shoot Bergers in Lapua Match cases, Federal GM primers, benchrest prepped.  I can't do better than about .75 MOA with my 3-9x40mm scope that it wears in normal recon configuration. The .4s are with me behind a 6-24x50mm Burris target scope (Japanese glass) with 1/8 MOA fine target reticle.  The trigger is an SSA-E.  1.2 lb. second stage.  Not a true target trigger, but this is a multi-purpose rifle.

Get higher magnification and good glass.  Use a very fine reticle for that work.  Resolving fine detail at distance is as important as magnification.

Yea, mixed brass is an obvious weak point.....Might get 50-100 Lapua or maybe prep some LC with same head stamp all the same....then anneal.

Eliminating crimp and trying new primers should be tried.

Was just shocked by initial 2” groups during break in.

There are two different kinds of Lapua brass.  Know this when ordering  Their standard brass is very good.  Their Lapua Match is exceptionally consistent and is true benchrest quality.  Never crimp match bullets where sub MOA is the goal.

I have a Rainier Ultra Match 18" SPR profile that will do what you're looking for at under $400. It loves 77gr SMKs.