Build Thread Diamondback's AR build (planning/construction)

[Diamondback]

Inspired by Joe's 10/22 build-thread, I'm starting one for my AR.

Tools in hand:
--Wheeler AR Ultra Armorer's Toolkit - AR Armorer's Ultra Kit - Battenfeld

Lower parts in-hand:
--NWFA Anderson lower -
--PSA Classic LPK - Palmetto State Armory Classic LPK - Black - 6983
--uncertain origin, PIF'ed mil-spec buffer assembly
--DS Arms castle nut - DS Arms - DSA AR15 Buffer Tube Lock Ring/ Castle Nut
--YHM Extended Takedown Pins - EZ Pull Takedown Pin Set
--Magpul BAD lever - B.A.D. Lever® - Battery Assist Device – AR15/M4
--KNS anti-walk FCG pins - KNS Hammer and Trigger Pin Non Rotating AR-15 Small Pin .154 Inch BLK
--FAB Defense combined recoil-pad/rear monopod - Monopod Buttstock Add-on - MBA
--FAB Defense GL-MAG stock - M4/AR-15 Survival Buttstock w/Built-in Magazine Carrier - GL-MAG
Enroute
--FAB Defense Ergonomic Folding Grip - Ergonomic Folding Pistol Grip for M16/M4/AR-15 - AGF-43S
Questions:
--Are there any particularly good or bad castle-nuts to seek or avoid, or is it just pretty much "one CN's same as the next"?

Upper assembly (initial) in-hand
--DS Arms BCG/CH combo - DSA AR15 M16 Type BCG and Alloy Charging Handle
--Badger 249-02 tactical charging-handle latch - Tactical Latch - Gen I
--FAB Defense foregrip/bipod with light - Tactical Foregrip with Integrated Adjustable Bipod and incorporated flashlight - Gen 2
--Precision Armament AFAB-556 flash suppressor - AFAB Hybrid Muzzle Brake - Precision Armament
Enroute
--CBC Industries upper - AR-15 UPPER ASSEMBLY - 16" / 5.56X45 / 1:7 / MIDLENGTH / 15" CBC ARMS KEYMOD GEN 2 AR-15 HANDGUARD / RAIL
Questions
--Given that I'm working with neither bench nor vise, other than Go and No-Go gauges for headspace, what do I need to know or acquire to perform a barrel swap?

Upper assembly (post-rebuild)
Planned
--Palmetto .223 Wylde nitrided midlength barrel
Debating
--Blast Deflector: Indian Creek BFD or Kineti-Tech?
Questions
--Given that I was contemplating a muzzle device nestled inside the end of the handguard, and I'm light sensitive, I need to balance "lateral flash reduction" with "overall flash reduction." Most of the 17" handguards I've seen are "slimlines" with a 1" inside diameter, so I'm not sure if a linear comp at .988 has enough safe clearance between its outer wall and the HG inner. Should I be looking more at a linear compensator, or just make do with a 15" handguard and a traditional flash suppressor? (Bear in mind, I'm trying to plan for the worst case scenario--darkness, indoors, and so light sensitive I need polarized lenses in just normal room light.)

Sights/Optics/Mounts in-hand
--Optic: Bushnell TRS25 - Bushnell - TRS 1x 25mm
--Optic Riser: Leapers UTG 1" - Leapers, Inc. - Hunting/Shooting, Sporting Goods and Security Gear
--BUIS:
-------Front Polymer Diamond Front Sight (with NiteBrite)
-------Rear Polymer Diamond Rear Sight (with NiteBrite)
Still need
--Laser Boresighter

I'll add pics and updates as decisions are made and construction commences. In the meantime, would appreciate advice on narrowing things down--I have the feeling that brakes/flash suppressors alone will be a whole post later in this thread by themselves.

Read More

 

[BlackdogGS]

Here: Build It Yourself - AR15.COM

Also, your fash hider should extent beyond the rail. If it's tucked inside the blast can split the rail like a banana.

image url

 

[Diamondback]

Right, I was thinking not all the way in, but about a quarter- to half-inch of MD beyond the rail, though with a Keymod or M-Lok HG the front slots would also provide ventilation. Sound sufficient, or does it need to be completely outside?

As for ARFCOM... *cringes, shuddering* though that reaction may be more to a late and unlamented arsewipe relative who spent way too much time around there and trying to push them.

 

[BlackdogGS]

Right, I was thinking not all the way in, but about a quarter- to half-inch of MD beyond the rail, though with a Keymod or M-Lok HG the front slots would also provide ventilation. Sound sufficient, or does it need to be completely outside?

Personally, I'd make sure it's completely clear of the rail. I have seen pictures of split rails that were well ventilated. Rails are expensive.

 

[BlackdogGS]

One of my builds. 16" barrel with 15" rail.

screenshot windows

 

[Diamondback]

Very similar to how I envision Phase 1 to 1.5--nice build! Assemble your own upper, or was that a prebuilt?

TBH, the only reason I went to thinking of 17's was because I couldn't find an eight-side at sixteen... Then again, there's what, an inch of barrel length inside the receiver? (Based on quoted length Black River Tactical quoted me on their Covert Comp of 17.4" from comp muzzle to receiver front face on a 16" barrel with the CC itself being 1.95" of that, that says that the combined chamber/receiver and thread/MD overlaps add up to 1.55" if my math's right.)

 

[BlackdogGS]

That rifle has an all Brovo Company upper that I assembled. To install a barrel you need a barrel block of reaction rod, much on YouTube. I have all this stuff, if you need help let me know.

I'm working on a new build with an Aero upper/lower and LaRue barrel. AR building is an addicting curse.

 

[Diamondback]

Appreciate the offer, but I'm a ways out up by Seattle. TBH, I'm not really an AR fan myself but I seem to find myself with reasons to put ever more on the build list...
--This one
--A .300BLK pistol
--Replicas of a current-issue M16A4 or latest M4 for me, and a Canadian-standard C7 or C8 for my gal if we can figure out how to keep her legal on it (his-and-hers set, the C-models because she's a Canuck)
--At least one SPR or DMR clone
--A jiggered "built-to-fail-safely" replica of an early-issue Vietnam M16 (the idea here is once I finish my degree and start teaching, something to give my students the head-banging frustration of the Vietnam experience without any of the danger)
--A non-buggered functional version of same, in memory of deceased friends who served Over There
--.22LR "trainer versions" of any of these that are likely to be pressed into Homestead Defense service, or at least a dedicated matching .22 upper for each

This look about right for barrel block?

Upper block with receiver insert and gas-tube aligner--Wheeler calls it "perfect for torquing a barrel on or removing a stubborn barrel nut."

 

[BlackdogGS]

Yes, that's the barrel block I have.

 

[timac]

Right, I was thinking not all the way in, but about a quarter- to half-inch of MD beyond the rail, though with a Keymod or M-Lok HG the front slots would also provide ventilation. Sound sufficient, or does it need to be completely outside?

As for ARFCOM... *cringes, shuddering* though that reaction may be more to a late and unlamented arsewipe relative who spent way too much time around there and trying to push them.

If you want to put the flash hider somewhat into the rail, buy a blast diffusser. These are designed to send the blast forward, away from those around you.

 

[BlackdogGS]

This might work too. Noveske Flash Hider KX3 Pig 1/2-28 Thread AR-15 Parkerized

 

[Diamondback]

So, what I've fed into my spreadsheet so far... Diameter matters because the only 17" eight-point HG I've found having a 1" I.D.

Sub-1" O.D.
.84x1.5 AR Performance JAL
.863x2.25 Griffin M4SD Linear Comp
.865x2.225 Precision Armament AFAB-Mini (discontinued)
.866x1.95 Black River Tactical Covert Comp
.866x2.26 Precision Armament AFAB-556
.95x2.125 Kaw Valley Precision Linear Comp
.97x2.24 Troy Industries Claymore (brightest flash in tests)
.971x2.125 DPMS Levang Linear Comp (discontinued)
.988x2.95 Hera Arms LC Small Linear Comp
BRT tells me the CC was designed for applications almost exactly like mine, other than the flash consideration--but it was designed to fit inside pistol HG's, so at rifle length there should be less flash, right?

1"+ O.D.
1x4.334 Griffin XM Linear Comp
1.09x1.75 Midwest MI-PBD
1.2x3.25 Noveske KX5
1.22x3.55 Hera Arms LC Gen 2
1.35x1.8 Thordsen BD-180 Blast Deflector
1.35x3.28 Noveske KX3 "Flaming Pig"
1.49x3.1 Indian Creek Design BFD
1.608x2.315 Ferfrans CRD

Right now, I've been scoring things with an index of one point for each tenth-inch of length above 1.55", same for each tenth of diameter and each tenth of an ounce weight. I haven't looked at the flash test scores at this point, I'm just scoring on dims and weight--and would appreciate any ideas for better scoring systems y'all might have than my simple "point for each tenth".

 

[Joe Link]

Very cool!

 

[Diamondback]

Upfate, right now I'm back to thinking 15" HG, 16" bbl with a Precision Armament AFAB-556 flash suppressor.

 

[Diamondback]

Castle nut, BCG and charging handle ordered. Updating OP.

 

[BlackdogGS]

Upfate, right now I'm back to thinking 15" HG, 16" bbl with a Precision Armament AFAB-556 flash suppressor.

Smart way to go. I love the slim hand guards. Get a quality barrel.

 

[Diamondback]

Smart way to go. I love the slim hand guards. Get a quality barrel.

Phase 2 is either the Palmetto nitrided 1:7 mid-length 16" Wylde or same specs if I can find 'em someplace like Faxon or Ballistic Advantage.

Phase 1 is just get something Up & Running before this Blue Hell does something unbelievably stupid... I wish they'd all go protest a nuclear test by chaining themselves to the bomb.

 

[Diamondback]

OP updated with new arrivals, purchases and decisions.

 

[Diamondback]

Updated with upper and assorted other parts on-the-way. Construction expected to commence Sunday.

 

[Diamondback]

Latest enroute parts added... construction delayed until Wednesday since some lower parts arrive Tuesday.