Now that I'll be leaving California soon I can start getting my plans together for my AR15.  I'm interested in putting together an AR that I can use for IPSC competitions.  

I would appreciate information on where I can find reviews of the various manufacturers components, or comments on your experience.

I would like to build it so that I can use both 5.56 and .223 rounds (so the gun is capable of handling the higher pressures of the military ball ammo).

Thanks

I can give a few comments from my experience.  I have assembled a few ar's, some for fun, one for competition.  One thing is for sure...you get what you pay for.  Stay away from generic parts/kits.  I have found that while they may work just fine, they do not compare with quality parts and kits from some of the reputable manufacturers, ie. Bushmaster, Armalite.  

When I assembled my competition rifle (DCM), it was trial and error all the way.  It was also my first ar.  I tried various parts from different sources and manufactures.  I ran a DPMS barrel, Eagle Arms lower, Olympic upper rec., Bushmaster bolt carrier group, float tube, and Rock River trigger and sights.  I was very happy with the quality of most parts, they all fit together like a glove, finish overall was very good.  I was not happy with the barrel.  I had to send it back once for a rough chamber.  It had some deep marks left from the chamber reamer when manufactured, so-much-so that it would ruin my brass that was fired through it.  DPMS replaced it promptly (I sent it back almost a year after I purchased it too, glad to see them stand by their products).  I still have not been too thoroughly thrilled with the barrel however.  Perhaps it is just me and my ammo, but I have yet to get the accuracy I would like out of it.

Another rifle I built for fun has an ASA lower, DPMS bolt carrier group, no-name flattop upper, no-name lower parts kit, and bushmaster 16" barrel.  That barrel rocks.  Everything I have put through it, it has eaten like it was it's favorite candy.  Even my fodder ammo, it shots and groups better than my comp. rifle.  The no-name parts almost look defective.  Poor fit, sharp edges.  The upper looks to be out of spec., not much, but I would never expect to see parts like those on real military contract weapons.  None the less, it was extremely cheap, and still works very well.

My brother shoots an Armalite DCM rifle.  My friends shoot a Colt HBar, and Bushmaster respectively.  If/when I were to assemble one again, I would go almost exclusively with Bushmaster and Rock River components.  All I need is time and money.  Don't we all.

Thanks for the info!!

How do you spell IPSC?

I shoot High Power and don't know much about IPSC to be of much use.  I started out using a DCM Garand and hung out with the croud and gleened a lot of info that way.  The best info is don't buy cheap shit and don't expect expensive shit to make you good.

Are you a USPSA member?  If so the last issue of Front Sight had a lot of info on a big 3 gun match.  Don't know if this matters to you or not, but it seems that most of the big name IPSC shooters are now using 18" barrels.

I'm guessing this is with the midlength gas system.  I've also heard that it is a little easier to make power factor with an 18" barrel than a 16" barrel.  I'm new to 3 gun so I can't tell you much else.

As for parts, do like what was said above, don't buy cheap shit.  Although I do have a J&T kit and it has been great.  The parts are much better than a Model 1 kit I assembled.
Scott