This build was inspired by two existing uppers I have been looking at, but neither seemed quite right for me. The 14.5" SOCOM M4A1, and the 18" SPR.

I want the stability of the heavier barrel, but not too heavy, or too long (front heavy).



I already have a 16" middy with the A2 barrel profile, and I like the overall ratios of handguard length and gas system length to barrel length. I like the pinned A2 front sight base also. This is my current 16" middy, it was a project I put together a couple years ago with the Ballistic Advantage barrel, it's 1/7, melonite finished.










For the new build, I ordered a barrel kit from TNTE Sales. I'll finish it up with a free float tube, probably the YHM Black Diamond, and the Surefire three-prong tuning fork up front.

I'm hoping it will turn out to be a fairly tight shooting AR with the heavies.

I'll take you all along on the build, as it goes along, and the load work and accuracy results.

So here's the beginning of it, the barrel kit is on the way, It's a 1/7, 4150 steel, melonite finish.

16" mid length gas system is tough to beat. I do prefer a light weight barrel to carry around . I have a midweight 16" and it's not much more total weight and seems to shoot just a tad bit better.

kwg

Yeah, I was kind on the fence between medium contour and HBar, but since I do have the A2 contour already for a lighter carrying option, I decided to go full HBar.

It will be heavier, but I believe it should still balance pretty well.

I don't know who developed the first 16" mid length but they deserve a pulitzer prize for one of mankind's greatest inventions.

kwg

Hmm. They seem to have a good selection of parts & barrels. Thanks for the heads-up!
https://www.tntesales.com/

Yeah they have a lot of the retro parts too, seems that is getting popular.

I remember when TNTE started up a few years ago, A firefighter owned outfit. Stood out to me because my dad and brother were both career firefighters.

This is actually the first time I've bought from them. I was looking for a specific type of barrel, and they had it.

Did you get it built ??

kwg

No not yet.

I'm discovering that TNTE Sales is not the place to shop if you are in a hurry. My order is still 'Awaiting Fulfillment". I placed the order on 31 Dec. They indicate 7-10 business days is typical, so I'm being patient here.

I'll definitely be sharing here when we get some forward movement.

Well I got a UPS tracking number. Label created, not on the truck yet.

I've multiple 16" Middy's,but wayyyyyyyy prefer 18" rifle systems.

Far less fickle and much smoother.

And quieter......................(grin)

16"s, or better yet, 14.5"s, make good, handy vehicle guns; for most other use, I'd rather have an 18" any time.................lots of lighter weight / mid-weight 18" barrels & handguards too, no need to have a 9 lb gun.

MM

Tough to beat handy/dandy and Rifle Gas...............

Got 18" er in process right now targeting about 6 to 6 1/4 pounds. Adjustable GB & after I get it tuned in with a full weight BCG, I'm going to take the 1st plunge into dealing with a LWT BCG version..........................if for no other reason than I can.

MM

I like commonality.................

Sometimes when things get boring, gotta try a blonde instead of a redhead................good news is, you can always go back to what worked before if things go to hell.

MM

I've seen me dabble.................

I'm sure there will be an 18"/rifle along the way. I still like the 20" rifles too, even though they aren't cool anymore.

20's don't piss me off...but I do reach past them on the average,to tote an 18" instead................

I've got barrels 10.5", 14.7", 16", and 20" represented.

I have an itch for a 12.5" pistol too. That and an 18" would hit most of the lengths between 10 and 20". I don't have any interest in shorter or longer than that.

Probably my favorite in the handy/dandy category is this 14.7", mid-gas.

18" is just a very nice place to be,for performance(75's at 2800fps is a breeze),parts wear/tear(Rifle Gas is your friend) and noise..........................

My ears hurt,lookin' at the picture.

I never know when a target of opportunity is gonna present itself...nor do I waltz around in 'muffs or 'plugs..................

18' er's....................







MM

Nice.

Looks Middy....................

There's no denying they get louder as they get shorter. It's all relative.....grin,

I've had 14.5", 16", 17", 18" with intermediate gas and a 20".

For me it's 16 or 20.

I like Slim Shady purty good,but shoulda went Rifle Gas on it's 18" LW contour.



Got the cart in front of the horse on that one...but the fhuqking thing SHOOTS,so I'm stuck in transition..............(grin)

That'll work. They're easy to like when they shoot great.

I prefer Rifle Length FF 'tubes on 18's too.



Not shabby...............

Nice! I like that paint too.

I know Stick doesn't like muzzle devices much, but to my ears, a bare 16" muzzle seems a lot louder than a 16" with the A2 muzzle device.

I really don't find my 14.7" with A2 muzzle device to be all that rude.

I'd be VERY impressed,if someone had more disdain for Loudeners...than I!...................

Good eye..........yes, the bottom one is mid with an adjustable GB. Top one is rifle gas.

new one being built is actually 18.8" with rifle gas & AGB.

Using an AGB on a middy mitigates some of the recoil impulse & gets it to shoot about like rifle gas, but with still a little more port pressure.

MM

Equal to equal, MD or not, an 18" gun a definitely quieter than any way you can do it than a 16 is other than suppressed.

Unless you actually shoot them side by side, it's hard to believe it would be as much as it actually is.

But on an LR gun I want as much reduction in muzzle jump as I can reasonably get w/o going to some of the really extreme breaks.

MM

I'm happy to add mass,rather than noise................

Yeah, that works, too.

But I ain't puttin' no barrel like that on any AR

MM

I savvy the stance..............

You weathered in today?

MM

Reloading,bolting new schit together and tying riggin'...while fighting the Flu.

Chrome in the AM.....................

Yeah, I hear, you.

Checked fit on most of the parts for the new build, MUR upper, Aero lower, nice & snug & I've used that combo before, SLR rail & AGB, Rise SS barrel & BCG, CMC trigger, Seekins safety, etc.

Got some Seeking rings I wanted to use, but think I will need a cantilever mount for the scope I'm likely going to use, so the rings will prolly get stowed. I'll use the rings on a smaller scope later.

MM

Playing MUR,Harrison spout/bolt,multiple stock,triggers and FF 'tubes.

Am good on 22BR,6BR,224 Grendel,243 Grendel and day old James spout 223 fodder now. Tying hooks,sorting vests,charging batteries,sharpening blades and swilling NyQuil....................(grin)

That NyQuil schitt will knock your azz out.

Snuggle up next to momma, have some honey & JD, & get some extry sleep.

MM

Sounding like 15# rain........................(grin)

Parts came in, and I have them assembled. I'll be upgrading the handguards, but we'll start from here.

I like the weight and balance.

MM,
I like the heavy 3 prong flash killer. Just right for shooting under night vision.

I've never tried one of the prong style devices. I always thought they look nice. This is a Surefire device.

What I'm curious is if they actually help accuracy by dampening barrel harmonics.

Parts kit does include the front sling swivel, I just didn't install it. Might down the road.

Saw it off, put the swivel on a float tube.

That's always an option. And I have considered it.

I have a hard time shaving down the FSB though. I could shave it down easy enough, but I just like the old school FSB.

Right now I'm thinking along the lines of a Daniel Defense Omega 9, two-piece floater. I don't mind knocking the pins out of the FSB to install a one-piece floater, but I kind of like the option of occasionally removing the handguard for cleaning, without having to unpin the FSB.

If I could come to terms with shaving the FSB, I could have it all, except the old school FSB. That FSB is part of the signature look of an AR15, and probably the most durable front sight/gas block option.

I don't like the sling on the FSB because the barrel walks so much under sling tension.

If you want to keep it that way, you could always rig the sling by wrapping it around the D ring. Called a "poor man's float tube" rigging.

I hear you on the sling tension, but the reality for me is I don't do much sling shooting anymore. I've gone to bipods for front support 99% of the time.

I'll still practice using a hasty sling. The loop-sling.....those days are over for me.

I won't cut anymore FSB's either. I like the pinned gas block and solid sight but I'm not going to pay $300 for a rail that's cut out for a FSB.

Both of mine are carbine gassed Colts and it wouldn't look right but on a mid, I think I'd try cutting out a section on top and let the FSB pop up through the cut out. I've seen a couple of jobs that turned out well.
https://www.m4carbine.net/showthread.php?128947-Custom-Noveske-14-5s-hacking-up-some-NSRs

If you keep it like it is, Way of the Gun sling is your answer.
https://frankproctorperformancegear.com/frank-proctor-heavy-duty-sling/

If you really want ti keep the FSB & be able to take the HG off w/o unpinning it, these work well..........direct replacement for a traditional plastic handguard. I've used a longer 15" version on a carbine gas gun, but they don't seem to make a similar version for a mid-length system, just this shorter version.

When it's on it every bit as solid as the plastic version.............just not a floated tube & still has those limitations if you can live with that.

MM

Drop in HG

That looks nice.

I put one of those on my 7.62x39. It's rock solid. It's something I'm also considering for this middy.

I love pinned gas blocks,but hate IRONS and always look forward to that chop.

The 'lug gets chopped second and a "regular" swivel stud gets mounted on every FF tube................

This is the only one I have that doesn't have the old-school FSB/gas block.

The 14.7" middy.

I don't have ANY that do.................(grin)

I don't know why I want to keep them on there myself, I can't see a clear front sight anymore anyways. I just like it.

I'm a fan of Smoothicity...................

First shots. 52 yards, 5X prism. Bipod/beanbag on Magpul polymer handguard.
4300 ft, 20F, near calm.

75gr Hornady BTHP over 24.0 gr XTerminator.

Four 5-shot groups on paper, first three sub-1", got sloppy on the last one.

Not bad for a new barrel. I need to make a decision if I want to float it or not. Leaning toward floating it.

Very nice

After I sighted it in, I did some plinking out to 300 yards or so, Upper functioned great. I put the rifle lower on for the first run to have a pretty rigid lower, and give the rifle a good chance to perform.

I'll be getting some on-paper results out to longer distances eventually, curious to quantify results out around 500 yards or so

Certainly nothing to complain about.

The absolute number one thing you can do to ensure a static zero is a free-float handguard.



Montana Marine,

Troy Delta Rail is what you want.

From a few years ago.


Colt M4 with Geissele SSF, SWFA SS 3-9x, A2 FH, and using MK262 Mod1 ammo. The test was that the gun was zeroed at 100 yards on a NRA B8 bull from sand bags, with over lapping bulls replaced each cycle. 20 rounds were used to confirm zero (2x10), and then two rounds per 10 different positions/rests/attachments.

Standard KAC handguards on left, the exact same gun with drop in Troy Delta rail on right.

That's a real difference.

Is the Troy product significantly better than similar two-piece floaters from Daniel Defense (Omega), or Midwest Industries?

Educate me.

When considering free-float rails, it is my perception that its job is to stay in place and not break. Why would I spend $250 on a rail that does those things no better than a $70 rail?

Neither MI not DD make an extended FF drop in.









I am unaware of a $70 drop in, free float extended rail?


As for a what a rail should do, it’s a bit more than stay in place and not break, however it may not matter for your uses.

I was over at the Troy website looking around, the only mid-length Delta rail I see is the M-Lok style. Having two M-Lok float tubes already, I'm not a fan. I find I'm always working around the gas block, or even barrel contact with the M-Lok bolts.

So, Quad Rail for me. Is the Troy MRF a decent rail?

I wouldn't mind a mid-extended tube with the FSB cutout, but not to keen on the M-Lok style.

Are you sure it was MLOK? Troy’s VTAC Version looks like MLOK but is not. However, the answer is to use KDG Kinetic rails for MLOK.



In any case, it doesn’t apply to the Delta Rail setup. Look how the rail is designed.

To answer your last question- the MRF is fine as a handguard but if you are going to get rid of the FSP there are better/lighter/stiffer rails available.


If you want to have a drop in free float handguard, the Troy Delta or Charlie rail is it.

Thanks for the pic, I'll look at the mid VTAC.

I'm keeping the FSB. I see a 9" MRF available on Troy's site. I thought that would work on my mid-length.

I have a mid gas VTAC I can send you to check out if you want. Just sitting in a box.

Thanks for the kind offer, but I'll just make a purchase.

MM, you mentioned contact with the barrel and/or gas block and it made me suspicious of my own setups. I'm using inexpensive full-length free-float rails of the keymod persuasion on two rifles (soon to be four), and one is particularly skinny. Sure enough, I have a device attached to the rail directly beneath the gas block on that rifle. I was able to verify that I have at least 20 thousandths of an inch clearance between the gas block and the keymod backing nuts. I suppose that's enough. I have not used any M-Lok stuff so I can't say one way or another, but keymod may work for you better than M-Lok. If you're inclined to go with either of the systems, that is.

Thanks for the info on that, I've never had anything keymod. I've pretty much decided for me, it's going to be picatinny quad rail.

OK, time to get back to this project and finish it up.

I ended up picking up a YHM Diamond free-float quad rail. So I'll be knocking the pins out of the FSB to put it on. no biggie, I've done it a few times before. Already have the pins soaking in Kroil.

I upgraded from my basic tools (barrel blocks/armorers wrench). Bought a Magpul Bev Block, and a PRI barrel nut wrench. Should make things go pretty smooth.

I'd saw off the the sight,retain the pinned 'block and drive a FF tube that covered same.

That thing even looks loud.....................(grin)

if you weren't aware, use a big punch to start the pins. lotsa folks try to start 'em with a tiny pin balanced and it goes badly. (grin)

Screw the punch, push them in with a pair of Knipex smooth jaw pliers so much faster and easier. I put tape on the jaws it helps keep the pin from moving and gives protection to the metal once you make contact.

A block or clamp to hold the upper is useful too...................

MM

I was referring to removal. Pliers don't really work for that.

MCH just woke up a little early & confused today

Cut him a little slack..........................

MM

I always use a big punch to loosen the FSB pins. Like I said, I've done it a few times.

I can't hear ya, my ears are ringing......grin

The Bev Block does stabilize the upper. It locks in to the barrel extension, and the bolt carrier slides over the aft of the Bev Block.

Here's a decent little vid that explains the Bev Block, and the Reaction Rod,

I LOVE pinned 'blocks...but Loudeners hurt me................

hey it happens.

Here's a pic of the upper receiver, set up in the Bev Block, pulled off the muzzle device first.



Pulled the gas tube, then laid down the FSB on a wooden block to knock the pins loose. One good rap is all it took, after soaking in Kroil overnight.



Back in the vise to remove the FSB and swap out the old barrel nut for the new,





Using the Bev Block, flipped upside down and used in the mag well,




Finished, Will get some paint on it when it warms up a bit more.

No you are right they don't! I use the proper size punch and never had a problem. I was thinking the pins were out and work was in progress, getting things back together. My mistake. It was afternoon here in Slovakia when I posted it.

OK, this rig is now in it's final form. Took it to the Icebreaker for some open country play, and that ACSS reticle was right on the money out to 800 yards with M855.

Primary Arms 1-6x24, 5.56 ACSS reticle
Burris PEPR mount. (just learned they also send smooth ring tops along with the pic tops, went with the smoothies)
YHM Diamond free float tube.
Surefire three-prong flash suppressor

Looks fine, MM. Nice work!

Looks good to me. Can you see your front post? I can see it on my HBAR. Gonna take a cutting wheel to mine.

I can see the front post at 1X, but PEPR mount is tall enough to put the reticle center above it. At 2X the post is hardly visible, at 3X it's not visible.

The ACSS reticle is second focal plane, and is calibrated for use at 6X.



I had initially gone with an AR-Stoner 20 MOA mount from Midway. It is significantly lower than the PEPR, and the front post was in the way at low power.



On the PEPR 30mm mount, the scope centerline is 1.6" above the receiver.

With the AR-Stoner mount, it is only about 1.4" above the receiver, and with forward slope. It is a no-go for a rig with a fixed front sight base and low power optics.

I haven't measure my old Armalite mount but it blurs the Nikon I have on their right now. On my M4 build I put a YHM flip up front sight. The HBAR has a postban front sight so I'll just cut that for the time being. I'll keep track of the mounts you listed. Good info.

Armalite is one of the lowest out there at 1.25"
http://www.maxicon.com/guns/optics/one_piece/ar15_onepiece_mounts.htm

Well that explains a lot. My cheapy Nikon is 4-14X so you can't really see it. But if the light is right then it distorts the target or whatever you're aiming at.

I had to put 1/2 inch of riser under my Armalite one piece scope mount. It just wasn't high enough for me to get a good sight picture.

kwg

That's a pretty good idea. I can get a decent sight picture but noticed when I have the mount on a AR with a collapsible stock it was more comfortable. Thanks for the tip, I'll look for a new mount when/ if I do an optics upgrade.