Remember to take what you read on the internet with a grain of salt. A prime example is a statement made in this thread...."RRA, Bushmaster, and DPMS don't stake carrier keys." My DPMS and my brothers Bushmaster came from the factory with staked carrier keys. Misinformation like this is what perpetuates internet rumors. I can't say every one is staked but mine have been.
I'll take your comments with a grain of salt since you list two rifles you have hands on experience with. I sold (conservative guess) over 400 AR-15s over the three years I worked firearms retail in a high volume shop. The DPMS or Bushmaster that had a properly staked carrier key was rare. Some had little dimples, but that doesn't stake the screws into the carrier key. Many carrier keys weren't touched at all. This isn't misinformation, nor internet rumor.
What really ticks me off is DPMS' LR-308 rifles. These rifles don't have the assembly issues DPMS' AR-15s have, which proves they know how to build an AR pattern rifle correctly. In fact I own a DPMS LR-308 that's configured very similarly to your DPMS AR-15. Hands on experience with my LR-308, and a good friend's LR-308 leave me with no doubt that your DPMS AR-15 is very accurate.
DPMS (or their contractor?) does a great job rifling their barrels. I wish they'd make sure their 5.56 chambers were in spec because I saw the gunsmith fix too many with a 5.56 chamber reamer set on the DPMS rifles. He could do that because most of the DPMS rifles didn't have hard chromed bores & chambers. We saw our fair tight chambered Bushmasters, but because hard chroming is standard on those, they had to be sent back to Bushmaster to get fixed.
A few years ago, the $600-$700 DPMS rifles were an okay buy if you knew the risks - have the gunsmith fix the chamber under the in store warranty if it needed it, stake the carrier key & RE castle nut yourself, and a $75 HPT/MPI bolt if you wanted cheap insurance. You could spend another $35 or so, and get the heavier duty mil-spec RE tube (aka buffer tube). Nothing else the price range offered a nitrided or hard chromed bore at the price point at that time. Alas, it's not 2008 anymore. It's 2011, and S&W is offering a properly assembled rifle with HPT/MPI bolt, and T/C 1:8 5R nitrided barrel for $600. A couple hundred more gets you a Spikes with all the proper parts & assembly, plus a 1:7 hard chromed Mil-B-11595E bbl. Colts can now be found for $1000 (give or take a few bucks), rather the scare price of $1200+. LMT ARs are easier to find now too. Daniel Defense & Bravo Company have busted onto the scene with the added value of cold hammer forged 1:7 twist Mil-B-11595E bbls, along with all the proper parts & assembly, at prices lower than comparably equipped Colts. There's this new company called Palmetto State Armory that's selling uppers (some with FN cold hammer forged barrels) which are assembled correctly on paper (customer reviews indicate it's a reality too) at great prices. DPMS & Bushmaster didn't get any worse, but their competition sure as heck got alot better.
