Garufa

  The way I've seen some folks scrounge brass at the range you'd think it was gold.

A brass magnet would be a real game changer.

I have the 18" AR Stoner barrel (fluted, black teflon coated) from Midway and am very pleased with it....as in sub moa accuracy with Wolf Gold.  I really don't know that you'll find one much cheaper in .223 Wylde.  If there was I would have bought it as I can be notoriously cheap.

Honestly, I haven't shot it enough to fully answer your questions but it is accurate enough at back yard distances like 10-15 yards and it does hit hard.  The cartridge goes in the grip along with a 25-shot clip.  There are a coupla good youtubes out there if you Google it.

  It would have to be stepped in such a way that it could only be removed from the front correct? If so, then the only way to ever change the dust cover would be to remove the barrel nut.

  If it was stepped then it only could go in one way.

What's really fun is unscrewing a buffer tube when you're not paying attention.  That retainer launches with incredible velocity.

  It is a Umarex Legends P08....http://www.amazon.com/Umarex-2251800-Legends-Pistol-Finish/dp/B00AU6D5IS.  Looks and feels just like the real thing.

Just toss them into an ammo can with a good seal and throw in a dessicant pack if you like.

  If I'm not mistaken SIG has more than one Federal contract as well...or their products are just very well liked among those whose bills are paid by US Treasury checks.  They might just have a little more juice when taking on the government.

You can't go wrong with a Shield.

  Says the manufacturer is "Original Equipment".  That's about as clear as mud.  I hope there's not really a brand of mag going by that name, but at that price it can't be Ruger.

Well, that's all I've got.  I do like solving problems but I've never even owned a Colt of any kind.  Hopefully, Mark@Sea will see this...he does know a thing or two about them.

Is it the slide stop spring?   http://www.gunpartscorp.com/Products/185200.htm

I bet that thing is loud.

  They have in Nevada.

Those Cabela's/Pietta New Army pistols are very nice.  You can get one with an extra cylinder or starter kit for $250 and free shipping.   FYI, those are always on sale. 

If you Google "ar lower assembly" the very first link it comes up with is the guide.  I hope this is the one you've been looking at.  Study the picture of the parts and compare to your parts kit as a couple of those spring do look very similar.

The ARFCOM guide is all you need.  It's got pictures and everything.  The only way you can mess it up is to let a spring-loaded detent shoot across the room.

  Let's not have any spoilers.

How does one get a street name of "pancake"?   On second thought I probably don't want to know.

EBRs are nice and all but they've got nothing on steel and wood.

Based on what that place gleefully charges for .22 ammo I'd never set foot in there to begin with.   As far as comparing pistols...you don't need to rub two brand new pistols together to do so.  I image they've had enough people scratching up the merchandise trying the same thing.      Is that all that happened between these two sentences?

  Let's keep it simple....YES.

RK puts up similar signs in Knoxville (sometimes).  It's a futile effort.