New tech and advancements are here. Whats the new best AR15 cartridge?

[thedarkknight]

We all have 223/5.56 and it's been around long enough. Even the military wants a new cartridge. There have been many advances and discoveries is tech, powders, aerodynamics, etc. If cost and availability were not an issue, what do you think should be the next cartridge standardized for the masses? https://www.shootingillustrated.com/content/the-complete-guide-to-ar-15-cartridges/

 

[TonyTheTiger]

223/5.56

 

[Jsp556]

What Tony said…

 

[Eli17L]

I think 5.56 is fine till we get new technology.
But I do like the 6mm arc.

 

[Im2bent]

You did not include a phased plasma rifle in the 40 watt range in your poll....

 

[thedarkknight]

You did not include a phased plasma rifle in the 40 watt range in your poll....

It wasn't SAAMI approved. I think it comes out in a couple months

 

[3rd Monkey]

With or without a full redesign?

If I could pick one caliber... 6mm Remington. As for the redesign, I leave that to the engineers.

 

[ArTeeKay]

I like 5.56 an awful lot for what it is, but if you twisted my arm and made me pick something else for the platform, .300 BLK is pretty cool too. Good performance from a very short barrel with both light and heavy bullets, plus super quiet suppressed? For the things I use an AR for, that's hard to beat.

 

[Crabcore]

I'm surprised the 6mm ARC is getting so many votes. After seeing some guys running them at a match recently and talking to them about their velocities, I left pretty unimpressed. I think that cartridge over promised and under-delivered on performance. I talked to several shooters who felt the same way, who had built a 6 ARC.

 

[RUTGERS95]

223/5.56

nailed it

nothing beats it for performance, cost, weight, and application

 

[The King]

It looks to me like this chart is all over the place - maybe I'm wrong. Did someone build exact identical 18" AR15's and shoot the highest performance factory round available in every one of them for these numbers?

Or did they guess. I'm guessing it was guess.

 

[Steve_In_29]

6.5G

I almost got into it and then the crazy along with sanctions choked off the cheap ammo.

 

[TonyTheTiger]

nailed it

nothing beats it for performance, cost, weight, and application

And reliability, and mags, and spare parts, and availability....

 

[TonyTheTiger]

It looks to me like this chart is all over the place - maybe I'm wrong. Did someone build exact identical 18" AR15's and shoot the highest performance factory round available in every one of them for these numbers?

Or did they guess. I'm guessing it was guess.

Agreed. Still trying to figure out the fast twist vs. slow twist 223 thing also.

 

[FWoo45]

Based on that chart the 6ARC looks better but I went with a 6.5G. There is no way I would ever replace my 5.56 guns with the 6.5G, but it’s a nice addition. I’d love to hunt with a short barreled and suppressed G. I’m in kali though so I put together an expensive (for me, a poor) and utterly useless rifle that is a lot of fun.

 

[The King]

I have had the .224v, 6.5G, and the 6mm ARC. I considered the 6.5g to the best of them. I felt the heavier bullets did everything I was missing out of a .223 platform.
I later kept the .224 V not because it was better than the 6.5G but because every gun store on the damn planet had ammo and they were clearancing it pretty much even during COVID.

 

[Mocadon]

Well, I picked 6.8 SPC. I'm just not interested in stretching a 2.26 COAL cartridge past 5 or 600 yards. I've studied the 6mm ARC and I'm just not impressed with it as a combat cartridge. Rather than going to a 20" barrel I went the other way and built a 12.5" piston 6.8 and suppressed it. At 500 yards a 110 VMAX is going 1,537 fps with 577 ft/lbs of energy. With 200 yd zero it's dropping 64 inches. My 5.56 with 75 gr HPBT from a 16" is 1,772 / 523 / 50.5". The 6.8 is smaller, lighter, and more lethal at typical combat ranges. It takes about 500 ft/lbs to punch thru a modern kevlar helmet.

For long range I went with a 6.5 Creedmoor, piston, with an 18" barrel, also suppressed. it's supersonic past 1,400 with 140 ELD-M's. That's plenty good for me.

For breeching and real CQB I run a 10" 300 Blackout, suppressed. Small, light, fast, and more lethal than 5.56 under 100 yards.

I just don't see why I'd want a 1,000 yard gun in an AR-15 format when for 1.5 lbs more I can have a 6.5 Creedmoor in a DPMS Gen2 format.

My 2 cents worth. Can someone invent a DPMS Gen2 300 WSM ?

 

[PBWalsh]

Best for what though?

Logistics - 5.56
External ballistics - 6ARC?
Quietest - 300BLK subsonic

I vote 556, logistics wins wars.

 

[JCARL]

I've tried most; 5.56 is tough to beat in an AR.
Seems to be a question of system optimization (5.56x45) vs. specialization.

 

[EMorr]

My vote goes to the 6.8SPC.

Comparisons like this never give the 6.8 a fair shake, these numbers almost 100% came from Hornady and from their data the 6.8 is using a 120 grain projectile with a velocity of 2460 FPS from a 16" barrel. The 6.5 Grendel is a 123 grain pill at 2580 FPS from a 24" barrel and the 6mm ARC is a 108 grain pill at 2750 FPS from a 24" barrel.

My own handload for the 6.8 with a 110 grain V-max is giving me 2643 FPS out of a 16" barrel and 2867 FPS out of a 24" barrel and I have made hits on paper at 1000 yards with that combo (10 round, 20"-ish group). Granted accuracy was not stellar but hey it's a V-max bullet traveling 1000 yards out of a autoloader built 100% by me. I also have worked up a load using 130 grain Berger VLD's at 2570 FPS out of the same 24" gun that I hope will give better accuracy.

If the 6.8 was compared evenly to the other "High Performance" AR cartridges if would show it true potential. It also has "relatively" cheap and readily available FMJ plinking ammo where a lot of the other cartridges do not.

6.8 SPC FTW!

 

[BipThatInstance]

Hard to beat the logistics of 556, period. I have taken part in one too many T&E programs with USSOCOM and also got dragged into one too many rabbit holes with wildcats to *not* treat wildcats with any sort of suspicion.

That said, I am a bit partial to 6.8 SPC, even if Mr. Holland is a major doucher about it. For an intermediate cartridge for SPRs I liked it a lot but still...556 for me overall.

 

[SRPowah]

I would pick different cartridges from this list for different purposes. For an overall "you can only pick one" choice, the 5.56/.223 hasn't let me down and can be found everywhere.

 

[hlee]

As much as I like 6.5G and 300bo, it’s hard to argue against 223/5.56 for a generalist semi auto carbine.

 

[Steve_In_29]

Grendel is nice for distance as well as hunting larger game but .556 tops it in all other areas IMO.
Lower recoil, higher capacity, lighter carry weight, availability.

Grendel tops 5.56 even up close...bigger bullets are better,

 

[3rd Monkey]

Grendel tops 5.56 even up close...bigger bullets are better,

I've never had the pleasure of shooting a Grendel. Quad taps still about the same as 5.56?

 

[TonyTheTiger]

I've never had the pleasure of shooting a Grendel. Quad taps still about the same as 5.56?

No.

 

[3rd Monkey]

No.

That's what I was figuring... Thanks.

 

[Mocadon]

6.8 SPC beats them both from an M4 or SBR or Pistol, and with a 30 round mag (Barrett or a Magpul in Six8 format) and it's a clear winner. 6.5 Grendel or 6 ARC much past 400, but that's what 6.5 Creedmoor is for. IMHO.

 

[Steve_In_29]

The people that voted "the Russians haven't upgraded" should remember that they actually did. That's when the 5.45 came out.

Though Kalashnikov has actually stated that he was simply going to improve the rifle a bit and update the x39 round with modern bullets and powders.

The switch to 5.45 was forced on him from on high as, though their testing found no advantage to 5.56, the leadership were paranoid the American's knew something their own people were missing.

 

[thedarkknight]

Well look like the army has a new Sig XM5 toy. Those who have 6.8 SPC may be in luck later with reloading supplies

 

[TonyTheTiger]

Well look like the army has a new Sig XM5 toy. Those who have 6.8 SPC may be in luck later with reloading supplies

Like what?

 

[thedarkknight]

Like what?

The bullet I'm sure there will be more availability and options coming and probably lower cost

 

[solocam]

for a military perspective I understand.556. lighter, can carry more ammo, and flat enough to shoot at combat distances. if going suppressed, its hard to beat the .300bo. crazy quiet

 

[StLPro2A]

We all have 223/5.56 and it's been around long enough. Even the military wants a new cartridge. There have been many advances and discoveries is tech, powders, aerodynamics, etc. If cost and availability were not an issue, what do you think should be the next cartridge standardized for the masses?

Peevishly, I'd vote .50BMG...and, yeah, I do have one on the AR platform. ARs are the Tinker Toys/Legos/Lincoln Logs of firearms. Do the two pin push.......pull....slap, maybe new mag, and you are totally transformed for duty. Cartridge offerings for AR15 platform have grown to the point one has to answer the all important question..."What are your needs, expectations." Clearing structures, defensive/offensive roles, punching paper, ringing steel, DRT hunting, what game, how many legs, what range? ONLY one or how many choices? And, you forgot the big boy options...458, 450......7.62x39.....the iddy bitty....22lr, 22mag, 204, 17.... 30AR had a lot to offer, save Remington promoting. Silly boy, choices are for wussies. The more the merrier. Get 'em all.

 

[winniedonkey]

We need more Raufoss type rounds. There's my answer

 

[346ci]

Hard to beat the .223 for the above reasons.

I've tried the 6.5g and 6.8, still using a 12.5" ARP 6.8 for deer and haven't seen anything in the ar15 platform that could replace it.

 

[Mocadon]

Hard to beat the .223 for the above reasons.

I've tried the 6.5g and 6.8, still using a 12.5" ARP 6.8 for deer and haven't seen anything in the ar15 platform that could replace it.

Yep. I'm running the 12.5" ARP with mid length gas and an Adams Arms Piston kit. Built it with Aero M4E1 receivers and a Troy SOCC 10.5" handguard. It's my favorite AR. Runs like a top suppressed or not.

 

[RUTGERS95]

The people that voted "the Russians haven't upgraded" should remember that they actually did. That's when the 5.45 came out.

Though Kalashnikov has actually stated that he was simply going to improve the rifle a bit and update the x39 round with modern bullets and powders.

The switch to 5.45 was forced on him from on high as, though their testing found no advantage to 5.56, the leadership were paranoid the American's knew something their own people were missing.

No advantages for their doctrine.

 

[Steve_In_29]

No advantages for their doctrine.

Despite our "doctrine" the American military has been trying to get our 5.56 to act like x39 for decades.

 

[Biggy]

6mm ARC vs 5.56 / .223

0-300-500 yds (12.5" inch -18-20" barrels) = 5.56/ .223 (30rd mags) = Okay
0- 600 - 800 yds+ ? ( 12.5" inch - 18-20" barrels) = 6mm ARC (25 rd mags) - Better penetration through barriers ? = *Overall* better ??
How does barrel life compare between the two ?

 

[RUTGERS95]

Despite our "doctrine" the American military has been trying to get our 5.56 to act like x39 for decades.

Can't argue that

 

[thedarkknight]

Agreed. Still trying to figure out the fast twist vs. slow twist 223 thing also.

I believe twist rates refer to bullet weight as fast rated usually correlates with heavier bullets and slower with lighter therefore higher velocity and less energy

 

[TonyTheTiger]

I believe twist rates refer to bullet weight as fast rated usually correlates with heavier bullets and slower with lighter therefore higher velocity and less energy

I'm sure that's what it's supposed to mean, but it's a dumb and potentially misleading way of presenting it.

 

[Baron85]

My choice is 223/5.56 because of availability. If the 6.8spc and 223/5.56 had equal availability across the board. I would choose the 6.8 for general purpose do everything rifle.

Most of my Ar’s are 223/5.56 but my favorite is a 12.5 6.8spc more energy and power out of a shorter barrel. I have no real need for an AR past 300ish yards except just to play.

 

[mikeshaw2]

The new new service rifle will probably change some of these answers once we have civilian versions and ammo has caught up

M

 

[TonyTheTiger]

The new new service rifle will probably change some of these answers once we have civilian versions and ammo has caught up

M

Not an AR15 cartridge, so no.

 

[SeaBassHWD]

Based on your chart, the 6mm ARC looks like the clear winner.

 

[Rocketvapor]

Hope this isn't a 'one and only' AR-15 poll.
22 Nosler using resized/converted 6mm HAGAR brass in a AR-15 small frame.
The converted 22 NOSGAR with heavy for caliber bullets, loaded long is faster than the alternative 5.56 options (even it's little brother the 224V ).
88 to 95gr .224 bullets loaded LONG,off a sled, 1:7, long heavy barrel.
If shooting 'competition rules' the 22N is at a disadvantage to the 5.56.

I have supplies that can easily be used for 5.56 and the 22N.
I reload.
Bullets, primers, powder and cases to wear out a few target barrels.

I will qualify my choice by saying my primary shooting objective is slow fire on paper at 600, 1000 yds.
If need be I can load 5.56 for the other uppers and applications.
I used to buy, when available, bargain factory rounds, but not now.

 

[EMorr]

Based on your chart, the 6mm ARC looks like the clear winner.

I don't know who made the chart but it is clearly biased in favor of the 6mm ARC. If you get rid of cartridges like the 300BLK subsonic, 450 BM and 350 Legend that skew the averages of recoil and bullet drop and don't belong in this conversation and then used data from the same barrel length for all of the cartridges. I feel like the results would be much more balanced.

None of these newer cartridges are head and shoulders above the rest in my opinion. I'd also be willing to bet you could find a similar chart from a few years ago that "showed" how great the 22 Nosler and 224 Valkyrie compared to the others before 6mm ARC came on the scene.

 

[TurboTrout]

223/5.56 seems like a pretty proven thing, why fuck with it?