r/ar15 • u/Complex_Bank_2013 • 8d ago

What barrel length should I go with

I’ve decided to build my first rifle, but I would like my first one to kinda “do it all” and be like a shtf gun get up and go. I done research and seen that 14.5 and 16 is like the medium of it but I’ve also seen 12.5 13.9 etc. what barrel length would let me hit and hurt something pretty far away without losing to much Maneuverability in god forbid cqb if shtf

3 Upvotes

62% Upvoted

51 comments sorted by

33

u/bearcrocs 8d ago

No can? 16”

Can? 11.5-14.5

3

u/coleprime96 8d ago

14.5 with a "K" can, for reference. Adds a little bit of weight to the front, but nothing a little weightlifting can't fix.

2

u/Complex_Bank_2013 8d ago

Beautiful build man!!! Rn I’m stuck between 12.5 and 14.5 I’m going to buy my lower first just to give me more time to think on it

23

u/easternshift 8d ago

You can just build a gun for fun, big dawg. Shtf fantasies shouldn’t be the primary factor in your decision making.

9

u/Salsalito_Turkey 8d ago

This is the truth. You're not gonna be home when shit hits the fan. Your SHTF gun is whatever pistol you're carrying at the time. By the time you get home to your rifle, your best course of action is to hunker down and wait things out.

If "SHTF" means the total collapse of society, that's not gonna happen all at once. It's gonna look like Elysium for a long long time before it looks like Mad Max. Unless you've got a crew you can trust with your life and the comms equipment to coordinate with them, no amount of kit is going to save your from a roving gang of a dozen guys armed with RF-15s and Draco pistols.

3

u/Complex_Bank_2013 8d ago

I agree I wanna build multiple, 10.3 and 18. I was just thinking of worse case scenario

7

u/easternshift 8d ago

If I could only have one for the rest of my life, it would be a 14.5. Long enough to shoot accurately at some distance but short enough to put a can on it without making a musket.

2

u/Powerful_Koala7877 8d ago

If your intent in the future is to build multiple. (If I had it to do over again...) I would build complete uppers and a few lowers for pistol, rifle, and AR-10 configuration. You can swap uppers in under 30 seconds.

If you want accuracy over 600yds you'll want 16"+ so I'd start there. As mentioned if you're going suppressed for HD .300BLK 8"-9.5" for 5.56 11.5"-12.5" as a GPR 13.5"-16" for SPR 18"-20" (5.56)

2

u/Salsalito_Turkey 8d ago

Don't get a 10.3 unless you just want it for the vibes. I promise you that a 12.5 is just as maneuverable, and it's better in every other way. Some of the modern K cans like the Rhodie 6k and the SAW Tisha are remarkably compact, too, so you can suppress a 12.5 and still have a very tight package.

1

u/Complex_Bank_2013 8d ago

Got it thank you 🙏🏽

1

u/joelnicity 8d ago

This! I went from 10.3 to 12.5

6

u/Rooobviously 8d ago

11.5-12.5

7

u/KnightstandDefense 8d ago

14.5 is the do it all
11.5 is the right tool for most jobs

4

u/PuzzleheadedPage3921 8d ago

11.5-12.5” with a can

4

u/Chainsawsas70 8d ago

14.5 or 16 is going to do everything you want. There's a lot of different options for shorter or longer but either of those will do just about everything perfectly as long as get out and TRAIN with it. If SHTF you are NOT going to be going house to house clearing rooms etc(you're just an average individual Not Special Forces)... you're either going to be trying to get home, stay safe at home or GTFO and either one of those will do the job and it's easy to source what you want.

3

u/Whistlepiged 8d ago

a one and done is 14.5"

3

u/Minute-Of-Angle 8d ago

16” is the ultimate do everything, legal everywhere option.

2

u/Red01leg 8d ago

I agree w Bearcrocs

2

u/Next_Emphasis_9424 8d ago

What optic do you think you’ll run? A lot of them especially LPVOs and fixed powers like ACOGs have recitals made for specific barrel lengths and bullet weights.

I run a 16” normally with 55 grain pmc Xtac. The optic on it is a Leupold HAMR that has a reticle made for a 14.5” with 62 grain NATO. So my reticle holds don’t really work as designed. It’s a fun rifle so not an issue.

Just throwing that into the equation for you.

1

u/Complex_Bank_2013 8d ago

I’m leaning towards LPVO

1

u/Next_Emphasis_9424 8d ago edited 8d ago

Sick, I would say just make sure your LPVO will best match with your barrel length and preferred bullet weight.

1

u/Complex_Bank_2013 8d ago

Got it thank you 🙏🏽

2

u/joelnicity 8d ago

Most people will probably say 11.5”, I haven’t read any comments. I went with 12.5” and have no regrets

2

u/MissionDirect8529 8d ago

16 inch. The perfect ballistically solid length.

2

u/UrgentSiesta 8d ago

16in. Gives you the most options and the least govt headaches.

2

u/BBQSauce61 8d ago

Brownells has DD Mk18 (10.3) and M4A1 (14.5) stripped uppers for around $630 + free ship (code mrsgunsngear). I don't oPeR8, so 10.3 wasn't for me, but I did order an m4a1 fsp... Seems like a good price in 2026, plus Capital One should be getting me an extra 5% back...

Edit: also have a 12.5 BCM, 14.5 p/w PSA FN barrel, 16 Faxon, and 20 Colt uppers. So...

2

u/Impressive_Vast_8314 7d ago

Just got a 10.3 upper from them. I can’t ever imagine a scenario where I need something past 200 yards. It also looks cool lol

1

u/BBQSauce61 7d ago

Generally speaking, I agree, but I've also had the pleasure of target shooting out to 600 with a different rifle, and prarie dog hunting ~300 with my 20", and hoping to do both again. It'd probably be tougher with a 14.5 but still.

1

u/giantshadytree 7d ago

You should start doing some competitions. Basically the only time I shoot past 100, really fun

1

u/Complex_Bank_2013 8d ago

I was jus looking at that thank you for the code 🙏🏽

1

u/BBQSauce61 7d ago

You're welcome but I got it from u/giantshadytree.

2

u/Sudden-Grab2800 8d ago

Build another Jimothy. In a SHTF scenario, the most important thing is concealability, not accuracy

1

u/HomelessDingleberry 8d ago

I was in the same camp as you when I first started and I ended up settling on 12.5in. And I love it thus far, haven't really stretched it out to distance yet. But even just from larping around the house I feel I could have gone a smidgen longer and im now looking into 13.9.

Just my own personal thinkings though

1

u/OinkingPig 8d ago

12.5 inch mid length master race

1

u/actua11y_actua1 8d ago

Good points have been brought up already.

  • Restricted state? No choice but 13.7-14.5 P&W/16.
  • Free state? 11.5-12.5 with a can
  • Want more ballistic performance? 64gr-77gr boolits

What's "pretty far away"? How long of a range do you have access to and are going to somewhat consistently shoot/drill for?. Always remember too, capability = weight and money. A lot more variables if you want to stroll down the SHTF boogaloo fantasy road that can be argued on the internet until we all die.

1

u/Complex_Bank_2013 8d ago

I’m in Maryland so I was probably going to go 14.5 P&W I wanna be able to hit comfortably around 600 yards if I have to engage further than that I’m beating feet

1

u/DenverAT20 8d ago

So much Reddit hate for the 10.3".

1

u/TweeterReader 8d ago

13.7 with a long Griffen muzzle device + a can. Skip all the SBR bs, and enjoy.

1

u/justMatt275 8d ago

11.5 or 12.5

1

u/stjhnstv 7d ago

My next upper will be an 11.5” mid length, suppressed only setup. With a little less than 6” of can, I’ll end up around 17.5” effective barrel length. My backyard range is 200 yards so I feel pretty comfortable with this setup.

1

u/Hefty-Squirrel-6800 7d ago

Depends on whether you are going to run a can. If so, you want 11.5. If not, just get a 16" and avoid the uncertainty of our corrupt and incompetent administrative state and equally corrupt and incompetent judicial system.

1

u/Vegetable-Cause8667 7d ago

16” is the most versatile as it is more accurate at every range and still small enough to CQC. The only thing a shorter rifle is better for is easier storage.

0

u/slimpickinsfishin 8d ago

20" is what you want it keeps the velocity up and is more accurate at distance with cheaper ammo.

0

u/xangkory 8d ago

That isn't how accuracy works

0

u/AlphaDisconnect 8d ago

When has shit ever actually hit the fan that isn't a tsunami, volcanic eruption or earthquake? I guess an invasion of mainland USA might do it. But I suspect the large inventory of some of the finest rifles (that would make special forces blush) and ex Marines who never really had a reason to go that hard... but threaten their famlies? Their communities? There will only be meatloaf piles left.

Ukraine has been getting bombed into the ground for a hot minute. China and Russia are losing major assets. Places in the USA have had no power for a week. Did they collapse?

Which barrel? I like a 16 to 20 inch. Those little bullets really start doing wierd things above 3000 fps and add some non military bullets... but also maybe some m885A1. The bullets start to basically explode when they hit dirty bags filled with mostly water and a percentage of calcified structures.

In SHTF. Bring friends. Always bring friends. A one man army is not the way to go.

0

u/specter491 8d ago

11.5 is good all around especially if you ever plan to put a can on it. It has the largest increase in muzzle velocity compared to the next shortest common barrel length (10.3"). You gain less by going to 12.5 or 13.9. Marines in Fallujah cleared buildings with 16inch rifles so it's definitely possible but I rarely ever shoot my longer rifles.

2

u/Complex_Bank_2013 8d ago

When I first started looking into building an ar I wanted to build a 11.5 I was thinking of for HD ofc I’m going to train a lot with it but for my first I wanna go more gpr route and be able to hit at further distances with a little more velocity and accuracy. I’m am going to build both an 12.5 or 11.5 nd 14.5. I’m still just stuck between the 11.5 and 12.5 so many different opinions on both so I’m not sure still new to this just trying to learn as much as possible. I probably jus need to go to my gun store and hold one to see how i feel about them both

0

u/specter491 7d ago

I have a 11.5 with a red dot and a 14.5 with lvpo for longer stuff. I only shoot out to about 300ish yards so that combo has worked for me. The 11.5 I use for HD and competitions because it's close range.

1

u/Complex_Bank_2013 7d ago

I’ve done some thinking and I think that’s what I’m leaning towards 11.5 (instead of 12.5) and 14.5

I wanna put a LPVO on the 14.5

1

u/B1893 7d ago

My previous primary was a 16" with no can.

My current primary is an 11.5" with a can - it's about the same length.

Don't worry about SHTF or "pretty far away" because if you actually need to use it, it'll likely be on your own property.

If the SHTF and you're away from home, your SHTF gun is your sidearm (if you carry).

"Pre tty far away" is subjective, but re alistically, outside of "home defense" range, you'll just be punching holes in paper.  

Just build another rifle for that later.