Assembling the parts, critique anyone?

[BrigandTwoFour]

Hey guys, this will be my first AR. I have a fair bit of experience tinkering with gun parts (nowhere near gunsmith…but I can tool around), and decided to go with a part gun so I just get what I want from the start and not have to buy a complete rifle and then change the parts I didn’t really care for.

The purpose of the rifle is going to be a general purpose shooter. Most shooting will be done at a range, but there is a fair probability that I will take it varminting (living in central Montana and all), shooting classes, maybe even some local competitions. As such, I wanted something that will give have a good balance of performance to longevity. Cost isn’t too much of a concern since I will be spreading the parts out over whatever period of time is required (within reason).

Thus far, this is the parts list I have gotten together. Please let me know if I am missing something that will be required for complete assembly.

Project Invictus

Upper Receiver Parts:
Spikes Tactical M4 Flat Top Upper
VLTOR Low profile gas block
Rainier Arms Extreme Tactical Compensator
Larue Tactical 12" free float
Magpul MBUS front and rear (alternate: troy BUIS, front and rear)
BCM gunfighter charging handle mod 4 (medium)

Lower Receiver Parts:
Spikes Tactical ST-15 lower (safe/semi markings)
G&R LPK
Geissele .154" Hi-Speed SSA Trigger
Magpul enhanced trigger guard
Magpul ACS stock
Spikes Tactical mil-spec buffer tube assembly w/ ST-T2 buffer
Ergo pistol grip or Magpul MIAD (haven’t decided)
Magpul B.A.D.

Accessories:
Tangodown Stubby VFG
Streamlight TLR-1
Magpul ASAP
Magpul PMAGs
Redi-Mod

Optic:
Trijicon RX-34 w/ 4.5 MOA dot (assuming something with a chevron doesn’t come out before I get to it)[i]

Undecided Parts (this is the stuff I’m still debating on):[/i]
Barrel - Toss up between BCM BFG 16" Middy, BCM Standard 16" Middy, Sabre Defense fluted Stainless Steel 16", or Centurion Arms 16" Cold Hammer Forged.

I frankly feel like the SD stainless doesn’t meet my initial requirements, but it’s in the same price point as the others (maybe a bit below) and offers the accuracy of a stainless…so it’s still in the running.

As far as a BCG goes, I was pretty much set on the BCM Auto M16 w/Ion Bond coating- right up until Spikes Tactical released their M16 BCG with the Nickel Boron coating. The prices are close enough for me to flip a coin, but I have never heard of Spikes stuff being HPT, and that’s a drawback.

Does anyone have input for this build? Perhaps help me choose a barrel here? Any words of wisdom on the BCG?

[ColdDeadHands]

why not go for a FailZero BCG? It seems to get great reviews.

[BrigandTwoFour]

The new ST Nickel Boron BCG is coated by Fail Zero, and costs a bit less than getting one straight from FZ.

http://www.spikestactical.com/z/index.php?main_page=product_info&cPath=63_67&products_id=388

I’ll admit I don’t know much about FZ. Most places I’ve looked seem pretty positive about both BCM and Spikes (politics aside). I figured a good bet would have been spikes hardware coasted by FZ.

[Polymerhead]

You will need a gas tube to match the barrel you buy. Otherwise seems like a complete list for a functioning AR.

[BrigandTwoFour]

Oh, here’s a dumbass question (feel free to give me a dumbass answer :P)

When it comes to flash hiders/compensators, is there a general standard as far as threading it onto the barrel?

I’ve only occasionally seen manufacturers mention barrel threading, and I really doubt these mount like an M1A.

Any insight?

[ColdDeadHands]

@BrigandTwoFour

The new ST Nickel Boron BCG is coated by Fail Zero, and costs a bit less than getting one straight from FZ.

http://www.spikestactical.com/z/index.php?main_page=product_info&cPath=63_67&products_id=388

I’ll admit I don’t know much about FZ. Most places I’ve looked seem pretty positive about both BCM and Spikes (politics aside). I figured a good bet would have been spikes hardware coasted by FZ.

@BrigandTwoFour

but I have never heard of Spikes stuff being HPT, and that’s a drawback.

I think you just answered your own question.

[ColdDeadHands]

@BrigandTwoFour

Oh, here’s a dumbass question (feel free to give me a dumbass answer :P)

When it comes to flash hiders/compensators, is there a general standard as far as threading it onto the barrel?

I’ve only occasionally seen manufacturers mention barrel threading, and I really doubt these mount like an M1A.

Any insight?

½”x 28 threads seems to be the standard for AR’s.

[Polymerhead]

@ColdDeadHands

½”x 28 threads seems to be the standard for AR’s.

Correct - if it’s a 223 Rem barrel and it says it’s threaded, it’s 1/2"-28 unless stated otherwise. Different calibers have different threads that most makers adhere to.

[BrigandTwoFour]

@ColdDeadHands

I think you just answered your own question.

To be fair, though. I see nothing on FZ’s site or at Rainier about the FZ BCGs being high pressure tested either.

One could say I should just get a BCM Auto and send it to FZ, but I don’t have THAT much money to spend, hehe.

[BrigandTwoFour]

Oh, and thanks much guys!

Much appreciate the info about barrel threading. Any other tips about barrels? Are my choices more than I’ll need, or are they just about right? Any other ones I should be looking at?

[spamsammich]

In my experience, the 16" Centurion lightweight profile barrel is a happy medium between the accuracy of a Noveske SS and lifespan of CL hammer forged barrels. My old Noveske Afghan could probably out shoot it with proper glass, but it was much heavier despite being shorter and it’s projected life span is shorter. Centurion HF barrels have a tapered bore so in theory they should be among the most accurate chrome lined barrels available. Monty makes some pretty impressive accuracy claims with this barrel and so far I’d say in the hands of a better shooter, one could corroborate those claims.

[ColdDeadHands]

@BrigandTwoFour

To be fair, though. I see nothing on FZ’s site or at Rainier about the FZ BCGs being high pressure tested either.

One could say I should just get a BCM Auto and send it to FZ, but I don’t have THAT much money to spend, hehe.

https://www.m4carbine.net/showthread.php?t=35550&highlight=failzero
I think it’s being mentioned there that they use mil-spec bcg’s that are mpi tested.

[Outlander_Systems]

Have you ruled out a Daniel Defense barrel?

[BrigandTwoFour]

@Navigating Collapse

Have you ruled out a Daniel Defense barrel?

Nope, not at all. I just haven’t read much about them. Most of my choices were based on ‘buzz’ that I could pick up between here, TOS, and various other places.

If they’re worth looking into, then I’ll definitely consider them.

I failed to mention in the opening post that while this rifle is mostly for plinking, some competition, and maybe hunting- I also want it to be suitable for bug-out situations. That’s why I’ve been looking at the fail zero coatings.

Again, thanks for the help guys!

[BrigandTwoFour]

@spamsammich

In my experience, the 16" Centurion lightweight profile barrel is a happy medium between the accuracy of a Noveske SS and lifespan of CL hammer forged barrels. My old Noveske Afghan could probably out shoot it with proper glass, but it was much heavier despite being shorter and it’s projected life span is shorter. Centurion HF barrels have a tapered bore so in theory they should be among the most accurate chrome lined barrels available. Monty makes some pretty impressive accuracy claims with this barrel and so far I’d say in the hands of a better shooter, one could corroborate those claims.

Since you brought up the lightweight barrel…

Is there any real practical difference between using a mid-weight barrel and a light weight? Would the light weight potentially wear out faster due to less heat dissipation?

[spamsammich]

for your purposes probably not. In theory, yes. This is not something I worry about much with a chrome lined HF barrel. I might if I had a select fire weapon, but this isn’t a free state.

[BrigandTwoFour]

@spamsammich

for your purposes probably not. In theory, yes. This is not something I worry about much with a chrome lined HF barrel. I might if I had a select fire weapon, but this isn’t a free state.

So, in other words, a lightweight barrel will serve me just fine- even with the occasional “let’s see how fast I can pull my finger” mag dump?

[BrigandTwoFour]

WOOT

Picked up my lower today, it’s now sitting on the table in front of me. I am imagining what it will become.

Only question is…what part next?

[BrigandTwoFour]

Thought I might give an update here. I’ve been working away in my basement. I’ve made some changes here and there to parts, but so far this is what I have assembled:

Lower
Spikes Tactical forged lower, did the set screw mod so that rear detent doesn’t pop out
Magpul ASAP plate
Magpul ACS stock
Magpul Enhanced trigger guard
Magpul MIAD, large back strap, no finger ridge
G&R LPK
ST-T2 Buffer

Upper
Spikes Tactical forged flat top upper w/m4 ramps
BCM gunfighter, mod 4 (medium latch)
Laser Engraved ejection door (MOLON LABE)

Next month I’ll be ordering Centurion Arms’ CHF lightweight barrel with the gas black pinned, and the rainier XTC

As far as things that have changed, I’ll be getting the new Spikes Tactical slim rail when it becomes available. Also, instead of the spikes BCG, I’m ordering the BCM M16 BCG with the ionbond. The light will be the Elzetta M60 with a Gear Sector mount.

Since I wrote up the original plan, I’ve gotten to go look at and experiment with various optics. I have decided not to use the RX series due to low light performance, and will be using an Aimpoint ML3 w/ADM cantilever mount (going to use the package deal from Grant)

Appreciate all the info I’ve gathered here. Ya’ll have been extraordinarily helpful.