I wanted to share the parts list for the AR that I'm currently building.  Feel free to let me know what you think!    

Upper:

• Aero Precision M4E1 Enhanced upper receiver (w/ ejection port cover & forward assist installed)


• 16" Ballistic Advantage "Hanson" profile 5.56 barrel w/ 0.625" gas block journal, 1:7 twist


• Ballistic Advantage gas block (pinned, w/ set screws)


• Aero Precision melonite mid-length gas tube


• 12" Aero Precision Enhanced Gen 2 M-LOK handguard


• Surefire Warcomp flash hider


• Radian Raptor charging handle


• Lantac Enhanced BCG (E-BCG), auto-rated, w/ nitride finish

Lower:

• Aero Precision M4E1 stripped lower receiver, Freedom edition, w/ 4-40 set screw for rear takedown detent/spring


• CMC single-stage trigger, 3.5 lb pull, flat face, w/ anti-walk pins


• Aero Precision enhanced carbine buffer tube


• Lantac UPS-S Ultimate stainless steel takedown pin set


• Norgon Ambi-Catch magazine catch


• Radian Talon safety selector (45-degree throw)


• Odin Works XMR 3 extended mag release button


• Phase 5 Tactical Extended Bolt Release V3 (EBRv3)


• JP Silent Capture Spring (SCS) system, standard weight, w/ buffer retainer pin


• Primary Weapon Systems ratcheting castle nut and endplate


• FAB GL-Shock stock (w/o cheek piece)


• BCM Mod 1 Grip

Sights/Lights/Mags/Accessories:

• Magpul MBUS Pro front and rear backup iron sights


• HoloSun HS510C reflex sight


• Modlite PLHV2-18650 flashlight w/ clicky tailcap


• Magpul M-LOK offset light mount, aluminum


• Magpul PMAG 30 Gen 3 magazines w/ window


• Magpul MVG foregrip


• Magpul MS1 QDM sling

The color scheme is all black.  It will have my initials laser engraved on the left side of the receiver, just above the serial number markings.

Yes, I know that a lot of the parts on my list are not mil-spec.  Yes, I am okay with that.  I am enlightened.

Okay, all kidding and Fight Club references aside, I'm hoping we can avoid the "solution to a problem that doesn't exist" and "if it ain't broke, don't fix it" comments here.  I know that a mil-spec AR is solid and reliable.  However, if I wanted a totally mil-spec AR, I could build one that way, or buy one of the many that are on the market (okay, maybe I couldn't buy one so easily right now, with everyone in the country snapping them up as soon as they leave the factories, but you get the point).  I didn't purchase these items because of the marketing hype behind them, or to be tacticool, or to impress my friends (I don't have any to impress anyway ).  I chose these parts because I like the functionality that they provide, and since I haven't found a rifle from a manufacturer that includes all of these specific features just the way I want them, I'm building my own.  

I'm new to this particular forum, but my experience with firearms forums in the past has shown me that they can easily become a hotbed for argument.  One man's "upgrade" is another man's "needless gimmick," and I'm not really here to delve into that debate.  We're all here because we love AR-15s, and we love tinkering on them.  There are those who are purists and believe that mil-spec is king, and I respect that viewpoint.  However, I believe that there is always room for improvement -- if there wasn't, we'd all still be driving Model T's.  I like to keep an open mind when it comes to upgrades, and I hope others can respect that.  These are the parts that, after much deliberation, I feel will best suit my needs, and if one of them doesn't end up working the way I want it to, I can easily swap it out for another one.  Thanks, guys and gals!

I think this thread is doomed to fade into obscurity

Probably so!    It is what it is.

That's the most important thing. At the end of the day it's your gun, not anyone else's. Make it how you want to. The manufacturers on your parts list are all good. Can't ever go wrong with an Aero M4E1 set. Ballistic Advantage is a great bang for your buck barrel.

Me personally, the only thing I would change would be to use a 15" handguard and not the 12".

I considered a 15" handguard, but personally, I just like the look of the 12" handguard/16" barrel combo better.  I like to see some barrel sticking out past the handguard -- personal preference, I guess.  

Anyway, I installed the BA barrel in the upper receiver a few days ago, but I didn't install the gas system because I knew I would be checking the headspace, and I didn't want to waste the roll pins in case there was a problem.  And guess what?  My Clymer 5.56 headspace gauges arrived today, and this barrel/bolt combo failed the headspace check.  Bolt won't close on the "go" gauge (1.4636").  Guess I'm one of the lucky few who got an out-of-spec part, or hit the tolerance lottery and got two components on opposite ends of their tolerance ranges.  I don't have another bolt or barrel to test with, so I have no idea which part is to blame.  I guess there are going to be some calls to BA and Lantac in my future.  Life is but a dream!  

Now I am with you there.  I have a 22LR upper with a 15" handguard and think is it homely as hell.  Unnecessary weight as well.

Yeah, something about the handguard being basically the length of the barrel makes it look odd to me -- too chunky up front or something.  To each their own, right?  Good point about the weight savings.  I ran the numbers on this build, and it should come out to exactly 6.4 lbs without accessories (i.e., sights, foregrip, light, and red dot), and 7.4 lbs with them -- unloaded, of course.  Not too terrible.  

I don't know why, but I've heard the ejector needs to be removed to check head space.  Might investigate first.

That's correct, and the reason for that is because the ejector will put pressure on the bottom of the gauge and could give you a false negative on a "go" gauge (and, likewise, a false positive on a "no-go" gauge). Before I performed the test, I removed the ejector and extractor and reinstalled the bolt in the carrier with the cam pin. The Lantac E-BCG also has a "domed" cam pin with a flat side, and I made sure to orient that flat face to the front, as per Lantac's instructions. Everything was done properly, but the barrel/bolt combo still failed. Thanks for the suggestion, though, man!

I wanted to mention that I created a separate thread here in the "Build It Yourself" section for discussion of the headspace issue, so if anyone has comments about that, we can discuss it there.  Since this is more of a general parts thread for my build, I don't want it to seem like I'm double-posting or anything.  Here's the link to the headspace thread.

On the subject of my parts for this build:  Man, when it rains, it pours...  I just noticed what seems to be a defect in the brand new Aero M4E1 Enhanced upper that I got, between the ejection port and the handguard mount.  It is a completely straight, vertical "slice" or crack in the surface of the receiver, behind the right end of the ejection port cover rod. It looks almost like a razor blade slice. From certain angles, it appears like the anodized layer is "bubbled up" around the topmost portion of the slice. Adjacent to this slice are what appear to be some forging defects in the aluminum, under the anodized layer. This upper is not listed on the box as a "BLEM" receiver, nor was it sold to me as such by the retailer from which I purchased it.  The upper came with the ejection port cover and forward assist already installed -- I have never even removed the ejection port cover rod in the few days that I have had the receiver. I am assuming that this mark was made during the installation of the ejection port cover, or perhaps it was simply a manufacturing defect that went unnoticed.  Here are some photos:

https://i.ibb.co/vkrT3jk/aeroblem.jpg

I submitted a ticket to Aero about it.  I'm not sure if they'll be willing to do anything about it since I installed the barrel and test-fitted the charging handle, BCG, and the handguard in this receiver before noticing the defect, but the rifle has never been used/fired, so hopefully they'll work with me to make it right.

I have the 16'" BA Premium Hanson barrel and use a 12" hand guard. I like the length of the hand guard. Never checked headspace on the barrel/bolt.

Bummer about the upper receiver. If you can send the URL for your picture, I'll post it in this thread. I believe you need 50 posts before you can do this yourself.

Yeah, I'm hopeful that Aero will work something out with me.  Thanks for helping with the picture, man!  Are you talking about embedding the photos so people don't have to click the link?  I was wondering why my photos weren't getting embedded...  The restrictions placed on new accounts here are rather frustrating.  I'm getting pretty tired of the 2000-character limit, since I like to be descriptive in my posts.  Are the photos not showing up when you click the link in my post?  I edited the upper receiver image link in my previous reply to reflect the true URL for the photo:

https://i.ibb.co/vkrT3jk/aeroblem.jpg

Does that help?

Photos of the build, partially done, with most parts test-fitted -- just for the hell of it while I wait on these companies to get back to me:



Still waiting on the stock, red dot, and Norgon mag catch.

Looking good. Be sure to mount a red or green laser, and a IR illuminator they come in handy.

Thanks!  I'm pretty happy with the accessories I've chosen, though, so I doubt I'll be throwing a laser on it.

So, I really wanted to like the Phase 5 EBRv3.  The reason I chose it was because it offers ambidextrous bolt catch functionality with a one-piece design.  The BAD lever (and others like it) attaches to the existing bolt catch lever with set screws, and that design always seemed a little too fiddly to me.  I liked the idea of a BAD lever that was one solid piece and would replace the bolt catch rather than attaching to it.  After installing the EBRv3, my impression of it was that it was a pretty stout little lever.  It functioned well and looked good to me.  However, I just couldn't get past how close it sits to this flat-faced CMC trigger.  I have fairly small fingers, and even so, my finger actually touches the EBRv3 lever while my finger is on the trigger with the bolt forward/locked.  I passed the rifle over to my wife last night and said "put your finger on the trigger."  I watched as, like me, she had to squeeze her finger between the EBRv3 and the trigger.  She looked up at me and said, "Oh...   Yeah, I don't like that..."  If I were wearing gloves, I'm not sure I could even fit my finger in that tight little space.  

Check it out.

So, it looks like I'll be swapping out the EBRv3 for a Geissele maritime bolt catch.  I like the large textured pads on both the upper and lower faces of that lever, and I think it will look nice.  I would probably have enough finger clearance if I went with the curved CMC trigger, but I have always liked flat triggers, so I want to keep the one I have.

For what it's worth, I think it's pretty lame that Aero advertises their M4E1 lower as "marked and milled to accept short-throw safety selectors" when this is how a 45-degree Radian Talon looks in the M4E1 lower when it's set to "FIRE."  It doesn't even point to the milled "FIRE" window -- just the line in between the two windows.  The only short-throw safety selector that would point to "FIRE" in this receiver would be a 60-degree.  Why they didn't just make the little window for "SAFE" smaller while making the "FIRE" window larger is beyond me...  Any safety selector set to "SAFE" is going to be horizontal, facing forward.  You don't need a 45-degree window to identify that.  If the "SAFE" window spanned about 20 degrees, and the "FIRE" window spanned the other 70 degrees, this receiver would look good with any safety selector out there, from 45-degree to 90-degree.  I really want to keep the 45-degree functionality of the Talon, but this looks so stupid that I'm seriously considering reverting it back to its full 90-degree rotation and just tolerating the longer throw.

Am I missing something here, or is this just a poor design?

The Norgon Ambi-Catch arrived a little while back, so I installed it and tried it out in my lower.  I'm really impressed with it -- it functions flawlessly from both sides and feels/looks really solid.  It fits nicely with the Geissele maritime bolt catch, too.  Unfortunately, the ODIN Works XMR 3 extended mag release was a disappointment.  The thing about it (and I'm assuming this happens with many extended "lever"-style mag release buttons) is that pushing on the end of the lever puts sideways force on the mag release button and causes it to bind a little in the hole.  I sat there inserting and releasing a mag over and over to test it out, and I found that about 50% of the time, the mag release button would bind up so tightly that it wouldn't depress and release the mag.  The button would just freeze up in the hole.  This is unacceptable to me.  Pushing on the top of the lever (directly above the mag button hole in the receiver) causes it to work flawlessly, but it completely defeats the purpose of having an extended release.  I'm really bummed because I have short fingers and I have to slightly alter my grip to press a mil-spec mag button.  However, I'm far more willing to do that than deal with an extended release that only works reliably half the time.  Anyway, I picked up a Geissele ultra duty mag release button (to match the maritime bolt catch), and I'm quite pleased with it.  Live and learn, I guess!  In spite of the few disappointments I've had, the rifle is coming together nicely.