I have had this urge for a while now that I cannot get rid of to put together a minimalist, lightweight carbine in 5.56. I'm not talking an airweight, ultralight gun with aluminum or titanium bolt carriers and that kind of stuff...just a simple, reliable rifle with an emphasis on minimalism.

My criteria:

- Flat top w/red dot optic. Retro builds are cool, but that's not what I'm after.
- 14.5" pinned and welded or 16"...no NFA stuff
- free-float handguard
- I do want a forward assist and dust cover...not going that minimalist

Other than that, the sky's the limit. What optics, mounts, barrels, muzzle devices, furniture, etc. would be best suited for that goal? Stock doesn't even have to be adjustable, because I'm 6'5" and always have them fully extended anyway, even with body armor.

A couple of specific questions:

1. A few companies I've looked at offer "pencil" barrel profiles, but also a lightweight duty-type option that's just a bit heavier (Faxon "Gunner" and BA "Hanson" are a couple of examples). Do these slightly heavier offerings offer enough advantage to justify the weight gain over a true pencil barrel?

2. What's the story on skeletonized bolt carriers? It seems like this is a reasonable way to shave some weight and reciprocating mass without turning to expensive or less-durable materials, but is messing with the weight of the carrier going to compromise the timing and reliability of the whole system?

If you want to build on a budget I used a matched Aero upper, lower, and rail with a BA Hanson 223 Wylde pencil barrel. The barrel has the .625 gas block. Trigger is a Larue MBT and a Toolcraft BCG. The gun is LW, accurate and is used for hunting pigs. I take the Aimpoint magnifier off to save weight when used as a defense type weapon.

I would stay away from the skeletonized BCG’s. I think they cycle wayyyyy too fast and need to be tuned.

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I would stay away from the skeletonized BCG’s. I think they cycle wayyyyy too fast and need to be tuned.

Thanks, that was my concern as well, but I have zero actual experience with them.

I had a friend throw together a pencil barrel 16" with a full length carbon fiber PRI free float tube for me and mated it to a standard lower with an MFT minimalist stock. I haven't weighed it, but it's silly light. I threw a Weaver 3-10 on it and took it out a few times. My opinion is it's too light to do much of anything at longer distances. Used it on a few ad hoc PRS style stages with some friends a few months back and couldn't hit crap with it out past 100 yards, it was just too light to hold steady. The least movement became input on the gun. I might try a red dot on it and shoot some PCSL with it, but it feels too "gamey" and I think I'd actually prefer to just shoot matches with my AR that's set up for actual practical use.

As it stands now, I don't think I have a valid use case for it, to be totally honest. It's light, sure, but... why? If I was trekking way out in the desert to snipe coyotes, maybe. I could probably justify putting my lightest suppressor on it for such a use, but the idea still doesn't move the needle for me.

What do you intend to do with it?

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What do you intend to do with it?

Close range run & gun type stuff. Just for fun, or maybe competitively if I can find a place locally that runs those sort of matches (not likely). It's hard to find places around here to shoot long range...my local club can go out to 200, but it's a PITA to do that the way it's set up, so typically I'm 100 yards and in. Would be nice if it could hold 2-3 moa...I don't want a repeat of my mini-14...but it doesn't have to be a sub-minute gun.

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Originally posted by 92fstech:

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I would stay away from the skeletonized BCG’s. I think they cycle wayyyyy too fast and need to be tuned.

Thanks, that was my concern as well, but I have zero actual experience with them.

They have their place in a tuned race gun. They are not designed to lower the overall weight of the rifle. They are designed to reduce the reciprocating mass that is the secondary portion of recoil you feel in an AR.

They must be paired with an adjustable gas block to be utilized correctly. They definitely don't belong in every rifle.

For what you are trying to do, I would use a 16" pencil barrel. I have one on a lightweight build that I built for basically the same purposes you outlined.

It's accurate enough. 2-3 MOA with factory 55gr. I didn't free float this one. Just slapped on a magpul polymer handguard. In addition to lightweight, this one was a budget build.

It's not a true dedicated lightweight build in that I didn't try to shave every last ounce off of it in every way imaginable, but my lightest AR build is this one, where I was aiming towards using mainly lighter/smaller components:

13.7" BA Hanson barrel with pinned SOLGW Nox brake, 13" CMT DRT free float rail, Aimpoint H1, Inforce WML, Magpul MBUS, B5 furniture, and BFG VCAS sling.

(I also have another AR that's nearly as light despite having a 16" barrel and 15" handguard, using a BCM Enhanced Lightweight barrel and MCMR rail with an Aimpoint T2.)

Here is my old school Colt with a 14.5 pencil barrel. It's not fancy but it's light and handy. I do wish it had the flat top receiver. Apparently, they weren't a thing in the 1970s.

I'm not a pro, so "grain of salt".

In the past, I've had good luck with Faxon barrels. They make a 14.5" pencil barrel with an integrated flash hider. total length is just over the magic 16". I will use the lightweight bolt carriers that many folks offer. I use a free-floating forearm handguard that is long enough to cover the gas block but not much longer (but I'm short so you may be more comfortable with a longer handguard). I use gas blocks that are low profile so I can use smaller diameter handguards. If the handguard seems too short and I worry about reaching too far forward...I add a short fingerguard made by Arisaka. Another option is to install a QD attachment at the forward end of the handguard (for your hand to bump into if you reach too far) Holosun red dot. The last one that I built came out below 6# which was fine with me.

While building my last one, I had a plain jane handgrip laying around so just for giggles....I drilled a bunch of1/4"-1/2" holes in the grip to see how much of a difference it would make in weight reduction. It didn't make much difference but I kinda like the way it textures the grip so I kept it.

I usually start with an H2 buffer but for my last build, I tried a KynShot hydraulic buffer. It probably weighs a bit less, but I didn't weigh it. Interestingly, it changed the recoil a bit. Made it "softer" ?? I'm not sure it reduced the recoil, but it's definitely different. Is it worth it ? Time will tell....

Sorry for the ramble....mike

This message has been edited. Last edited by: mike28w,

I’m also not an expert or really an AR guy, though I have a few. One is built on a polymer lower and a standard 16” flattop upper with standard carbine length gas/FSB and slim carbine handguards. To ME it doesn’t make much sense to go with a LW barrel AND insist on free-float handguard. Unless you can’t stand seeing the front sight in your red dot window. Even then you could use a cut-down FSB with standard plastic carbine handguards. To get lighter than that with a free-float rail and nut might be pricey or difficult. Again, I’m not really up on the latest AR goodies so take that with a grain of salt.

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Originally posted by RogueJSK:
It's not a true dedicated lightweight build in that I didn't try to shave every last ounce off of it in every way imaginable, but my lightest AR build is this one, where I was aiming towards using mainly lighter/smaller components:

13.7" BA Hanson barrel with pinned SOLGW Nox brake, 13" CMT DRT free float rail, Aimpoint H1, Inforce WML, Magpul MBUS, B5 furniture, and BFG VCAS sling.

(I also have another AR that's nearly as light despite having a 16" barrel and 15" handguard, using a BCM Enhanced Lightweight barrel and MCMR rail with an Aimpoint T2.)

Handsome rig. What’s the weight please

I'd love to have a 14.5 inch pinned and welded or a 16 inch pencil barrel with an A2 upper. Not an add on carry handle, but an A2 upper, and put an ACE skeleton stock on it for a light and practical gun for range and close up work.
I've got several to work with, but none have an A2 upper. That's my sticking point is finding one with a pencil barrel.

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Originally posted by 1KPerDay:
To ME it doesn’t make much sense to go with a LW barrel AND insist on free-float handguard.

For my purposes it's not so much about the barrel harmonics as it is I want a slim handguard and the ability to grip far forward using a more modern technique that's consistent with what I'm doing with my other ARs. For what I'm doing with this gun I'm not thinking it's going to make any difference whatsoever to mechanical accuracy.

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In the past, I've had good luck with Faxon barrels. They make a 14.5" pencil barrel with an integrated flash hider.

That's actually one I've been looking at. Have you actually used that barrel, and if so how has it performed for you accuracy-wise?

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Originally posted by IndianaBoy:

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Originally posted by 92fstech:

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I would stay away from the skeletonized BCG’s. I think they cycle wayyyyy too fast and need to be tuned.

Thanks, that was my concern as well, but I have zero actual experience with them.

They have their place in a tuned race gun. They are not designed to lower the overall weight of the rifle. They are designed to reduce the reciprocating mass that is the secondary portion of recoil you feel in an AR.

They must be paired with an adjustable gas block to be utilized correctly. They definitely don't belong in every rifle.

Thanks for the feedback...it confirms my concerns. Standard BCG it is.

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For my purposes it's not so much about the barrel harmonics as it is I want a slim handguard and the ability to grip far forward using a more modern technique that's consistent with what I'm doing with my other ARs. For what I'm doing with this gun I'm not thinking it's going to make any difference whatsoever to mechanical accuracy

ah, got it.

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Originally posted by 92fstech:

quote:

Originally posted by IndianaBoy:


They have their place in a tuned race gun. They are not designed to lower the overall weight of the rifle. They are designed to reduce the reciprocating mass that is the secondary portion of recoil you feel in an AR.

They must be paired with an adjustable gas block to be utilized correctly. They definitely don't belong in every rifle.

Thanks for the feedback...it confirms my concerns. Standard BCG it is.

Utilized correctly as part of a complete system they can make a rifle that shoots insanely smooth. Without sacrificing reliability. Over years of rifle competitions I have had maybe 5 malfunctions on the clock. Most of which were magazine related but probably one or two that were a result of a gun tuned for minimal recoil.

On other forums I have seen guys just toss them into a lightweight build as a way to shave ounces. Which is a big mistake, IMHO.

I have even seen guys pay extra for a low mass carrier, and then pay extra for a heavy buffer to try to mitigate how harsh the rifle is running. Just an absurdity.

The absolute best place to shave weight for a really nice handling AR is the barrel. And then the stock. Although balance is often more important for how a rifle handles while shooting than just pure total mass. But when that rifle is hanging on a sling, it's really all about total mass.

Depending on how far down the rabbit hole you want to go. There is a company called Smoke Composites that makes carbon fiber handguards and stocks.

https://www.smokecomposites.com/

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Originally posted by Jupiter:
Here is my old school Colt with a 14.5 pencil barrel. It's not fancy but it's light and handy. I do wish it had the flat top receiver. Apparently, they weren't a thing in the 1970s.

I didn't see the magical third hole until I came back to this thread this morning.

That's absolutely fantastic.

^^^^^
Thanks, IndianaBoy.
I have a number of AR platform rifles, including a 9" BCM .300 BO, and even with the 14.5 barrel, it still may be the lightest one of them all. I could make it even lighter if I replaced the metal stock with a polymer version. A modern version of this would make an extremely handy little package.

92fstech, are you ruling out all polymer one-piece lowers?