Im moving this post up here from the barrels section because after 24 hours lots of looks but no help - hopefully more exposure will help me get some ideas.

--------------------------------------------------------------------------------
Well this all started after a quest to replace the barrel on one of my carbines - it was a 16" douglaus, 1/9 twist, heavy under the guards, standard config barrel. My set up was a PRI front sight and I used a BMAS to free float the barrel, JP trigger, bushy lower, Eotech, GGG rear sight, ZM weapons y-comp. Rifle shot .5-.75 MOA all day with handloads and 1-1.5 with SA, Fed193, Q3131 and then I started having extraction probs when it got hot and dirty. Fixed that (mostly) and then groups began to open up so I decided since the barrel had about 4500 rounds and being a picky ex-master service rifle shooter, I'd rebarrel. Since this carbine is used mostly for shooting steel out to 300 yards and 3-gun matches, chrome was the was to go. Also, there's the fact that loading 223 is a pain in the ass and I'm shooting either factory ball or surplus (tends to be dirty stuff) almost exclusively.

I decided to go chrome this time. I have a few Colt M-4 barrels that all shoot less than 2 MOA with ANYTHING I feed 'em (with decent ammo 1.25 -1.5 moa is the norm), but decided to go with a JT, 16" M4 profile, heavy under the guards, chromed barrel due to cost and availability of Colt barrels. Well I pull my old barrel, replace the gas tube( I always do this when I rebarrel - dont know why but I do) and assemble the rest of the set-up as above. Groups SUCK! 6-8 MOA is best I can manage from the bench, pull the eotech and throw a scope on - no better. I try Fed193, Q3131, SA, Santa barbara no difference. I do manage a 5 inch group with Hornaday V-max, but that's the best I can do. So..

I call JT to tell them this Chromed barrel is a POS. They tell me that since I modified the barrel to fit the PRI, its mine for keeps. Ok, I'm pissed, but I can see their point. So..

I order a DPMS 14" from CMMG. chromed, 5.56 chamber, 1/7 on the recomendation that it would shoot 1.5 - 2.0 moa. Hell, I know nothing about chromed barrels - Kreiger's, Harts, Obermeyers - different story. Well using the same set up as the douglaus and the Wilson, I getting 4 MOA. So now I'm convinced, that I'm going blind, loosing the touch, and thinking that I need to SBR all my scatter guns to hit something. So back on goes the scope - same shitty groups from the bench. I pull out a Colt M4 barreled upper that has the same set up as above except it sports an Aimpoint- bang! I'm shooting 1-2 MOA even freezing my ass off with the wind blowing 15-20 MPH.

SO...

What do I do know? Get another barrel? From whom? WHat manufacturer? I've thought about getting a barrelled LMT upper from MSTN, but they havent shoot the 14 or 16 inches yet to be able to tell me how well they will shoot so I'm a bit leary to spend more $$ and be unhappy.

Maybe I'm just expecting too much, but my chromed barrelled AR's except this POS all shoot under 1.75 moa with ball - this includes free floated ones and non free floated ones(bushy and colt).

Just to update things, I called CMMG today and John more than made it right even without my aking him to - put them on your "good guys to do business with" list.


Thanks for your thoughts,

Jim

________________________________________
Smooth is Fast

Maybe it not the barrel that is the culprit.  Have you notice any excessive wearing on the inside of the receiver?  My friend rebarrel one of his uppers and clamped down too hard on the action block and damage the reciever and experience bad grouping.  The notch where the indexing pin going into, has that opened up at all? That will allow barrel twist.  The receiver extension area, is that loose.  This could effect accuracy as well.  Why don't you post this in the Troubleshooting section.  Tweak is the man you need to speak with.

223,

I was simply hoping that more exposeure here would lead to some answers quicker.  The indexing notch is tight, the extensions are fine.  I have even pulled and reinstalled both barrels twice and no change.

I'll post a "Tweak help" link in the trouble shooting section.

Does that mean your problem is solved 4mga? There are reasons that Colt barrels are more expensive.

I'm afraid to say that YOU are the problem, after all that Barrel swapping it should obvious by now that the Barrel is not the problem, maybe you are just loosing it sir.
Maybe too much coffee or something.

A quality Douglas Barrel is good for way over 4.500 rounds.

You see, "Tweak the Omnipotent" (made sure I spelled that one right[;)]).  Just mention his name and he knows of all problems undone.  Tweak, you really need some good theme music.

Tweak,

No the problem is not solved.  I still havent decided which barrel to try next.  I still have 2 barrels that dont shoot worth a crap.

Spiffy,

I had wondered that as well, but I've still 'got it' at least with my Colt and Bushy barrelled AR's.  I even had a friend that has one EVERY individual and most team trophies at Perry try the rifle with the JT barrel - he didnt fair much better than I did - about 0.5 moa better than I.  Now I could be pretty easily convinced that Ive done something wrong from an assembly point of view.  Of course, I've built or been involved in building over 15 ar's at this point, so I'm just not sure what I could be doing wrong.  Most have been match rifles that shoot under 0.4 moa or less out to 600 yards, so I have to think its a component issue in this case, but again Im open to suggestions.

I'm glad you are having good luck with Doulaus barrels.  I have found them to be great entry priced barrels for competition; entry being the key word.

I have this barrel, and I haven't had any of the issues you descibe.

Yes, they are.