Scoots,
I have a few questions for you on your issue and it is my understanding that trying to "tighten" the extension a "few degrees" is virtually impossible and here is why. The extension is screwed to the barrel then it is pinned in place with the indexing pin. To move it just few degrees would mean you would be redrilling almost in the same hole and it would become elongated.
Here are some thoughts:
It is my understanding that the headspacing is done off the extension not the barrel as you find on other rifles. Also when the gas port it drilled it is usually in line with the indexing pin and the only way to tell if this is the case is to pull the barrel from the upper and look at it. What can typically happen is that where the barrel nut goes on the upper there is a slot that the indexing pin fits into. Sometimes these are a bit wider than they need to be allowing the barrel to twist (a few degrees, sound familar) when the barrel nut with the delta ring are tightened. This is easily fixed by someone with the correct tools and knowledge. It isn't necessarily a hard thing to fix depending on who put the upper together and if it was done correctly.
What are your headspacing issues? I may have missed them in an early post. Typically the bolt headspaces on the extension, at least that is my understanding. What kinds of problems are you having? Many times issues thought to be headspacing issue can be traced back to case length, seating depths, brass thickness, etc.
Please bear in mind I am not trying to say you don't have a headspacing issue as that would be pretty foolish on my part not having inspected the weapon. But it has been my experience that is usually is not the culprit.
If you want feel free to send me an email outlining the problems you are having and I will see if I can point you in the right direction. I am not an expert by any means but have 5 successful builds under my belt, one being a switch barrel gun that uses 4 different barrels (and calibers) with only 2 different bolts all in the same gun.
If you don't want to do that then I would suggest finding someone in your area that is very familiar with AR's. Not to knock anyone but a lot of shops or gunsmiths can be excellent with semi auto sporting guns or bolt actions and not be familar with some of the "fine points" (read as quirks) that are specific to AR's.
I am willing to try to help if you want it. No guarantees but I am pretty sure we should be able to point you in the right direction anyway......
I wish you were in the neighborhood I would have you bring it over and we could tear into it to see if we could get you up and running as I like a challenge..... Nobody should have to go thru the frustration for year just to be able to shoot their AR...
DonT
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