I have a complete RRA M4 from years ago but I've always wanted to build.  So, my first goal is to find a lower.  Pretty confident I will go with PSA.  Still deciding on whether to go complete lower or stripped?????  I am slightly leaning towards stripped so I can learn the assembly.  That leaves which LPK to go with???

Next will be the upper.  Again, PSA is the front runner.  I'd like a mid length.  One thing I know I don't want is a fixed front site.  I want to either add an optic at some point or just get front (and rear) flip ups.  So, I don't want something I will have to dremel to remove.

I'd prefer to buy separate BCG and CH.  No idea what brand.  PSA or other???

Most likely go with Magpul CTR (or MOE) in FDE.  Again Magpul handguards and grip in FDE.  Not 100% on Magpul but I like their looks.  

This is more or less a budget build but not trying to get the absolute cheapest.  So, any other recommendations are greatly appreciated.

So, first step is just the lower.  There is a gun show coming up in 2 weeks locally but I haven't been to one in years and don't want to pay more than online plus FFL fee.  

If you go with a stripped lower you will be fine.

When I put mine together I literally had my browser on the instructions that are on this site.  I only had to refer to them when I was putting the safety detent in, needed to know the orientation of the detent (pointy side toward the safety).

As long as you read the directions a few times and watch a couple different videos (multiple o you see different ways of doing things) you will be good, just need to get roll punches that you may not have.  You should have all other tools for the lower.


As to the Lower Part Kit, LPK, I went with CMMG and was real happy.  If you go with PSA make sure you get the 'classic' kit.

One other thing, if you are leaning toward some cool pistol grip, stock, trigger, safety, or other do dad make the effort to get everything before you start assembling.  Really the only part that would be bothersome to take out and switch out would be the bolt catch, but that doesn't mean you want to be taking it apart every week or so to put something else on.

Have fun!

Shinji_Ikari - Thanks.

Here's my list so far.  
Lower

LPK

CTR

I was hoping to go with FDE for the stock, grip, magazine, and handguard but I'm a bit lost on the handguards.  

Reason is I can't seem to find the upper on the PSA site I want.  I want a mid without the front site or with an easily removable site.  And from what I've read, I would want the premium line????  Not the Freedom or PTAC.  Not sure what the difference is, it's just what I read.  Maybe I'm confused.  

Can anoyne help me out with the upper????

And I would then find a BCG and CH if the upper doesn't include them.

I think that's all but I might be forgetting something.

With what you have listed you are short a couple parts to complete the lower.

You will need the buffer tube assembly.  With the stock you have selected you will need a mil spec tube.  
NOTE - there is such a thing as commercial spec buffer tubes.  They work fine, but you have to make sure that the tube and stock you get match mil/mil, com/com

The whole assembly consists of:

Buffer tube
recoil spring
recoil buffer
castle nut
end plate
(also the buffer detent and detent spring which should be in the LPK)

As for the upper it sounds like you are wanting something with a low profile gas block and a free floated barrel.  Now to open up options for you, as long as ll parts are in spec you can use an upper from another company with the lower you are looking at.  The roll marks will not match, but as long as you are ok with that it is all good.

Here are some midlength gas tube options for you.
BCM midlengths

Thanks.  

Those BCM's look nice but a little more $$$ than I wanted to spend.  

So, none of the PSA uppers have a removable front site?  I may have to compromise on that.  

Thanks for the info about the buffer tube, etc.  I knew I left off some things but I didn't want to get too overwhelmed in the thread.  This build could literally take 4 - 6 months or so, so I have time.  

thanks again for your insight.

Yeah BCM is a little pricy.  From what you were saying it sounds like you are wanting something with a low profile gas block and free floated handguard.  Just google 'freefloated midlength upper' and you should get other options that are not as expensive.

The gas blocks on PSA upper receiver groups are removable but at that point I would just build the upper from scratch.

Have fun!

Aero limited edition "Freedom" upper/lower set

PSA "Defender" lower parts kit, w/polished trigger

ALG Defense Rail systems

I would recommend getting your buffer (H or H2), enhanced (chrome silicon) spring, and extension tube from Damage Industries.

Hope that helps a bit.