I'd be curious out of all the people that voted, how many own the cartridge they voted for? Or even several of them so they had some perspective and ability to cross examine.
-
Having trouble using the site?
Contact support
New tech and advancements are here. Whats the new best AR15 cartridge?
- Thread starter thedarkknight
- Start date
Well, I read the question as "What's the new best AR15 cartridge?". So, most folks never shoot past 300 yards, many never shoot past 100 yards. AR-15 Pistols are very popular amongst the non-precision shooting public. Hunting with AR15's is Coyote, pigs, and the occasional deer. I conclude the cartridge needs to run well in a 10" truck gun and a 20" rifle, needs to have maximum magazine capacity, needs to be lethal for deer and pigs, and needs to have factory ammo for those as well as plinking. And plinking is the #1 purpose for like 95% of AR15'S.
If cost isn't a factor, the 6.8 SPC fits right there perfectly. The 1% who want/need to shoot past 4 or 500 yards will always have the Valkyrie, Grendel, and ARC. The 99% who don't just want something that hits harder than 5.56, and the 6.8 SPC does just that.
If cost isn't a factor, the 6.8 SPC fits right there perfectly. The 1% who want/need to shoot past 4 or 500 yards will always have the Valkyrie, Grendel, and ARC. The 99% who don't just want something that hits harder than 5.56, and the 6.8 SPC does just that.
Past 500 seems like a mission for a large platform rifle/AR10
For killing things or just hitting them? I've got 6.5 and 6mm rifles and I still prefer 223 on steel to at least 700 yards. I've killed a few coons and groundhogs beyond 800 with 223 and 6mm and saw no real difference in killing ability.
Yep. I've got an 18" AA P2 (DPMS G2) in 6.5 CM, a 16" AA Evo in 5.56, a 12.5" ARP barreled Aero Precision with AA piston in 6.8 SPC, and a 10" home made AA piston 300 blk. I suppress them all with either an Omega 300 or a Griffin 30SDK.
Obviously, the 6.5 CM and the 300 blk are special purpose. I shoot the 6.5 to 1,000 almost exclusively, the 300 blk is CQB.
I only have the 16" 5.56 because of ammo cost and availability, plus broad compatibility in case of SHTF.
Absent NFA rules and ammo cost / availability issues the 16" 5.56 would quickly become a 14.5" 6.8 SPC. It's just a much better round.
Does the 223 even move the steel at 700, and can you hear it?
Also, at 700 my soft armor will probably stop the 223, at 800 it definitely will.
I usually turn my earpro up all the way to hear impacts at 500 (10-12” circle gong) if the wind is blowing a bit.
Yes and yes. 55gr much less than 69gr> obviously.
Found an old video of me shooting my sons 13.7" to 720ish yards. 5 hits out of 8 shots, 4 of them clearly audible, in a pretty stout and switchy breeze to boot.
Sure, .223 from a logistical standpoint. I'm not sure that really answers the question though:
If cost and availability were not an issue, what do you think should be the next cartridge standardized for the masses?
Maybe a high pressure round with case construction similar to the .277 fury, but scaled down a little bit to fit small platform rifles with .257 projectiles.
I'm a penny pincher. I'm not up to date on the latest and greatest, but I can rattle off the most cost effective ways to load up common calibers.
If cost and availability were not an issue, what do you think should be the next cartridge standardized for the masses?
Maybe a high pressure round with case construction similar to the .277 fury, but scaled down a little bit to fit small platform rifles with .257 projectiles.
I'm a penny pincher. I'm not up to date on the latest and greatest, but I can rattle off the most cost effective ways to load up common calibers.
That's probably fair, but I'd still be willing to bet that most people's understanding of a cartridges happy place comes from reading ballistic charts like the one in the OP, not from owning and or pushing the limits of all the cartridges being debated. Charts =/= real life.
The best overall cartridge for civilians, police or military ? For a new military cartridge out of 12.5" barrels to 20" barrels, for CQB out to around 1000 yds, **maybe** the new 6mm ARC. It checks a lot of boxes.
Interesting. It takes 500 ft/lbs of energy to reliability penetrate a ballistic Kevlar helmet. How much energy does a 6mm ARC have at 1,000 yards from a 20" barrel? At what range does it drop to 500 ft/lbs from a 14.5" STD M4 barrel?
Strelok says my 12.5" 6.8 SPC has 502 ft/lbs at 575 yards. My 16" 5.56 has 503 ft/lbs at 520 yards. My 18" 6.5 CM has 510 ft/lbs at 1,325 yards. This is with 110 gr VMax, 75 gr HPBT, and 140 gr ELD-M respectively.
CQB - 1k??
Reminds me of
I mean a 458 is great for some close range subsonic punch, but I don’t think I’d want to run a PRS with it
A 338 is good at putting power way down range, but wouldn’t want to be rounding corners in a house with it.
the issue with so many of these "better" AR cartridges, is that they have a lot of feeding/mag issues. And their performance is always below what is promised. One of the reasons why, is that for whatever reason, every mfg thinks no one wants an AR with more than an 18" barrel. Well, shorten the barrels and the performance suffers. No different than when the 20" M16 becomes a 14.5" M4 and the range and performance drops off.
I like the 224V and 6mmARC, but I think they make more sense in a bolt gun.
the 300BLK at least delivers what it promises, but high performance it is not. That has been the best "alternative" AR cartridge in my opinion.
I like the 224V and 6mmARC, but I think they make more sense in a bolt gun.
the 300BLK at least delivers what it promises, but high performance it is not. That has been the best "alternative" AR cartridge in my opinion.
I think a lot of that is due to its using the bolt and magazine the platform was designed for. I like the Grendels and variants of it but none of the latest and greatest cartridges utilizing non standard parts seem to have the durability and easy reliability of an AR in the chambering it was designed for. Which isn't shocking to me at all.
Isn’t the 6.8 SPC reliable in an AR? I’ve been thinking of adding one for the heck of it.
BTW, What does the poll results look like. I can’t see them if I don’t vote and yet I shouldn’t vote considering I don’t have or handled anything on the list to have a say.
I'm sure it's plenty reliable for the average civilians use, but shortly after it came out LWRCI and Magpul teamed up to make a proprietary intermediate frame rifle and magazines to "optimize reliability" if that tells you anything.
That was just to optimize reliability in cheap magazines. The standard AR-15 runs great with 6.8 SPC, much like 5.56, but reliable magazines (Barrett, a couple others) are comparatively expensive.
That may be so, but if a gun is picky about magazines or needs to be re-engineered to be at optimum function with cheap magazines it makes it sound like the gun was better off in it's original chambering. I'm not picking on just 6.8, 6.5G and 6ARC are too far from standardized and fully vetted over the long term for me to have enough faith in them to be my "stockpile ammo for the end of the world" guns also.
Yeah, it's the larger diameter cartridge body. It applies more force to the sides of the magazine causing bulging. Same for Grendel and I assume the ARC. Good quality steel magazines work fine but Magpul plastic would need to be too thick. So, they had, paid, conspired with, I don't know, LWRC to make a larger frame to hold a larger plastic magazine. Maybe that's what it took to get the Saudis to addopt it and buy 10's of thousands of the Six8's.
The Six8 didn't take off in the States due to the expensive proprietary receivers and mags. You can't load long in the pmags so no advantage there either.
I've used PRI, Barrett and ASC mags with no issues, hundreds of others do the same. I'd really like to see Lancer drop a 15 or 20rd 6.8 mag.
I've used PRI, Barrett and ASC mags with no issues, hundreds of others do the same. I'd really like to see Lancer drop a 15 or 20rd 6.8 mag.
Everything I hear about PRI, and Barrett is great. I have about 22 ASC mags and they work well but won't drop freely. Surprisingly, the 1 C-Products mag I have works best of all. It holds the most (28 vs 25) and when empty it drops free, zero sticking. I mostly practice tactical reloads so the ASC's not an issue when doing that, but still, grrr.
No, not really. Would you consider a 40 S&W pistol a bad product because it doesn’t work well with a 9mm magazine? It’s the same thing; that’s where the 40 started and it needed different mags from the get go, for the same reason as any of the larger AR15 rounds.
And any perceived issues with magazine cost are a result of availability. Compare those same “expensive” Grendel or SPC mags to the same product in 5.56, generally they cost the same.
Frankly though this thread seems to be full of uninformed opinions with very little fact. As you pointed out, most of the commenters here don’t sound like they have experience with more than one or two rounds on the list, but are certain that their opinions matter.
Lol.
Um, a lot of other AR15 rounds beat the 5.56 for performance. That’s the whole point here.
To some extent, I do consider 40 a bad product but not for the reasons above. I know shooters that have hundreds of thousands of rounds of both 40 and 9mm downrange in pistols based off the same platform. The 40 is absolutely more finicky, about mags and other things, and more prone to parts breakage. Is it because it's in a pistol designed for 9mm or because it's just got more horsepower? I think it could be both. Maybe a purpose built 40 pistol would be more durable and reliable. We might never know, and for a hobbyist shooter it doesn't matter, and those hobbyists that shoot 900 rounds a year always love to champion their favorite gear when they argue with the guys shooting tens of thousands of rounds a year. I feel like that same thing happens in these types of threads frequently.
I think of non standard AR chamberings in a similar way. Is a Grendel AR as reliable and durable as a standard 5.56 AR? In my experience and that of plenty of others, no. I would love to put 100k rounds of 6 or 6.5mm downrange like I nearly have with 5.56 to prove my theory that AR's in a long term high volume test work better in the chambering it was designed around but it's not financially feasible for me. If anyone else has I'd love to know.
None of this really matters to the average low volume shooter but I bet it might to the military.
That got kinda rambly, I hope it made sense. I'm not calling any of the AR chamberings bad per se, just saying that 5.56 and by extension 300BO, in my opinion because of it's geometry that allows for standard bolts/mags, seem to be the most easily reliable and trouble free especially with random assortments of parts and cheap mags, while the other rounds are more specialized and require a higher level of parts/understanding/tuning.
I wonder how well a Grendel or ARC would run doing 4 mag mag dumps on full auto, then letting it cool, then repeat until 6,000 rounds have been fired? I know the barrel will be toast, but what about the bolt and the carrier pin? 6.8 does very well.
I'd love to see it. I wouldn't be surprised if it didn't do well. Lucky for me that's not what I use mine for, and thus why even though I like both of those for my uses I wouldn't make it my "if I only had one rifle" rifle to stockpile ammo for like this thread topic is about.
You got me, I've got no experience with them. Does it run relatively trouble free for hundreds of thousands of rounds like 9mm in a pistol designed for it does? If it was designed around 40 and runs great then it kinda proves my point.
Well, it's hard to beat 5.56 but my little heart pounds at the thought of watching $30,000 of ammo getting wasted to prove a point. Lol. The 5.56, 6.8, and 300 blk will do well but for the same reasons 6.5 PRC burns barrels the others will have a tough time.
I really think purpose is the deciding factor. The AR-15 is a light weight mid range military weapon. If you shorten it's barrel alot for CQB then you really want 300blk, and that works well at short ranges. If you lengthen it's barrel for more range then you probably really want 6.5 Grendel or 6 ARC and they'll work better at the expense of barrel length and sustained suppressive fire. I'd argue 6.8 is a direct improvement for the original AR-15 purpose, and still allows for a little more range and good CQB performance, but the 5.56 is a tough one to beat.
I thought the DPMS Gen2 flavor of AR-10' ish receivers was great, but they seem to be more rare and I'm not sure why. Patent maybe? Isn't the Sig 716 a DPMS Gen2 receiver? I just wish we could have some AR-15 like standardization in the larger Stoner'esk platform. Maybe AR-10 standard? And 1 lighter frame? Because that's really what makes the AR-15 so popular, the standard.
Notoriously robust pistols in every caliber they sell them chambered in, but I don’t own a 40SW.
2.45" or 2.5 mags would be good with me
square out the receiver to where the notch is in mags.. sharpen the shoulder to 40 degrees
square out the receiver to where the notch is in mags.. sharpen the shoulder to 40 degrees
That's not bad. I'd still drop to a 20" barrel but it's a solid DMR choice. Probably also an excellent deer
, pig 
and coyote 
hunting gun. So, if you have a 5.56 for close in coyote and plinking, and you want an upper for deer, long range coyote, or pigs the 6 ARC looks like a good choice. I'm thinking if you're headed to Ukraine to meet up with James Yeager, kill Russians, just can't stand the AK, and have your own resupply, you're best off with a 12.5" suppressed 6.8 SPC like mine.
So it depends on what you're doing, who/what you're doing it to, and where.
But wear body armor.
Wise words for life......
Wear Body Armor video
Cost & availability not an issue + other than .223
I’d go 6ARC, 224Valkyrie, 6.8 in that order.
Caveat: I build my own gun.
I’ve got 5 of the not .223 calibers in the poll.
They all serve different things & have negatives.
Typically you only get the positive tag lines for each. So I’m going to list the negatives only for my calibers. They all run reliably & took varying degrees of effort to make that happen. Assume 100% reliable for all below.
Negatives:
6ARC - Pressure limited by Grendel type 2 bolt & lack of temp stable powder that delivers speed = to ball powder.
.224V - Brass life. Starline is best brass sometimes available. It’s good but not Lapua good. Same as ARC best speed for high bc heavies is with ball powder.
6.8 - Case capacity supports good speed @ max 120gr so it’s bc handicapped. 120 SST’s @2550 from my 16” is no slouch, but it’s no long range tack driver. Again ball powder is best AA2200. Mid range Hunter. I wouldn’t shoot a deer past 300 unless it was a zobie apocalypse & I was starving.
350L - Feeds like shit. Can be tuned to work reliably, but a PITA. It’s a deer gun that can be used in shotgun counties where I live. Dear to 200 max. Not a bad trade off for 200 with a pistol vs a slug gun. What the hell else would I ever use it for though.
300BO - Ballistic Turd like the Legend, but can’t use it in shotgun counties. Pigs = 6.8 all day, White Tail/Sika = 350L in shotgun counties or any variety of bolt gun in rifle counties. It’s great for CQB which I’ve had to do never. I did take a carbine class with it so there’s that, but essentially a short range play toy.
I like them all for different reasons. Only load for the top 3 cause I just don’t shoot the 350L or 300BO enough to make it worthwhile + the factory ammo works fine for my uses.
The negatives for the ARC & Valk can mostly be resolved. I.e. temp stability compensated for. Give up some brass life for performance etc. You can’t fix the others to make them perform at extended range.
I voted ARC. For my uses it seems the best balance/compromise for the AR magwell limit and delivers the best combination for long range target & small - mid sized game hunting.
I’d go 6ARC, 224Valkyrie, 6.8 in that order.
Caveat: I build my own gun.
I’ve got 5 of the not .223 calibers in the poll.
They all serve different things & have negatives.
Typically you only get the positive tag lines for each. So I’m going to list the negatives only for my calibers. They all run reliably & took varying degrees of effort to make that happen. Assume 100% reliable for all below.
Negatives:
6ARC - Pressure limited by Grendel type 2 bolt & lack of temp stable powder that delivers speed = to ball powder.
.224V - Brass life. Starline is best brass sometimes available. It’s good but not Lapua good. Same as ARC best speed for high bc heavies is with ball powder.
6.8 - Case capacity supports good speed @ max 120gr so it’s bc handicapped. 120 SST’s @2550 from my 16” is no slouch, but it’s no long range tack driver. Again ball powder is best AA2200. Mid range Hunter. I wouldn’t shoot a deer past 300 unless it was a zobie apocalypse & I was starving.
350L - Feeds like shit. Can be tuned to work reliably, but a PITA. It’s a deer gun that can be used in shotgun counties where I live. Dear to 200 max. Not a bad trade off for 200 with a pistol vs a slug gun. What the hell else would I ever use it for though.
300BO - Ballistic Turd like the Legend, but can’t use it in shotgun counties. Pigs = 6.8 all day, White Tail/Sika = 350L in shotgun counties or any variety of bolt gun in rifle counties. It’s great for CQB which I’ve had to do never. I did take a carbine class with it so there’s that, but essentially a short range play toy.
I like them all for different reasons. Only load for the top 3 cause I just don’t shoot the 350L or 300BO enough to make it worthwhile + the factory ammo works fine for my uses.
The negatives for the ARC & Valk can mostly be resolved. I.e. temp stability compensated for. Give up some brass life for performance etc. You can’t fix the others to make them perform at extended range.
I voted ARC. For my uses it seems the best balance/compromise for the AR magwell limit and delivers the best combination for long range target & small - mid sized game hunting.
I get that you're a 6.8 fanboi, you've made that clear in this thread. You've also made clear that you don't have much of a clue about any of this though, and are promoting the 6.8 because that's the koolaid you chose to drink.
The reality is if you can make a 6.8 run well, you can make a Grendel or any of its variants run well too. They're more alike than different in that regard, but I know you don't get that. Still, the fanboi crap is getting a little thick in your posts and a more astute person would be embarrassed about it.
Dude, that is true for ALL small cartridges. Every single cartridge discussed here shares that same attribute.
Well I can't argue with any of that except to say my fanboi for the 6.8 ends just past 500 yards. After that I become a 6.5 CM fanboi. And much past 1200'ish I'm totally open to suggestions.
LOL. Or you can't articulate whatever you actually meant.
I read what you wrote, I can't read your mind.
Similar threads
