Is it time to kick the 5.56 to the curb and upgrade to a modern cartridge? 

The sheer amount of this caliber that has been stockpiled by Americans over the last decade must be mind boggling. When half the country is sitting on thousands of rounds, this caliber is here to stay for a long, long time.

I own an ar in 5.56 for the same reason I own a 9mm glock. Both are great platforms with kinda okay, kinda shitty cartridges but at the end of the day if shit goes down there is a massive probability that the people next to me are gonna have the exact same shit as me 🤷🏻‍♂️

This guy shoots 80,000 rounds a year and if, and I mean if, I can find primers, they are priced at 15 cents each. This guy lives in a different world from the rest of us.

I was also a builder / defender in a combat engineer unit. We did MOUT training, lots of convoys, and did see urban warfare on our missions in OIF stabilizing Ramadi in 2005. I served with 0311 / 11Bs in Ramadi at various outposts and they had mainly M4s / M16 A4s for patrols but most of firefights they got into they used belt feds 249/240Bs to engage Iraqi insurgents from armored vehicles in convoys. I did see some of the 2ID guys with M14 DMRs and ran into some 2nd MEF snipers with M40 rifles, but everyone pretty much had M4 / M16s. I would say the most important thing was not the 5.56 caliber, but the fact the Army and Marines were now using Aimpoint / ACOG optics, but this was 17 years ago.

5.56 comes up short but not enough shorter to make a difference. The benefits of a lightweight rifle, ease of training, soft recoil and the ability to carry a lot of ammo trumps the slight improvement in ballistics that you get from another cartridge.

Folks, 9mm NATO is the world standard pistol cartridge and it’s over 100 years old. Law enforcement and civilian personal defense will keep the 5.56mm carbine relevant for the next 50+ years l.

The AR platform in 5.56 is loved because its stupid easy to learn and shoot... when you are talking about entire armies, that is preferred over some better balistics

It's logistics. 5.56 is fully integrated into our society. Just think of the sheer amount of 5.56 ar15 mags, bolts, ammo, reloading supplies, optics designed for 5.56, and all the police departments that use them. Probably the single best cartridge to stock as an American.

When I went to USMC Boot Camp in the early 70's we trained with M-14's Damn those things were heavy. Then we were issued M16's once we were in the fleet. I still love the .308, but my AR's are 5.56. 5.56 isnt going away in my lifetime.

It persists because ammo is plentiful and cheap. If I could get 6mm ARC for even close in price and availability I'd jump at it.

My father used m14 in vietnam his first tour, the m14 at first and m16 later during second tour. He praised the m16 for exactly the reason it's great, the ammo. When a sniper team could carry 1000 rounds for the m16 you cannot beat it.

5.56 can remain relevant for urban combat and such. It's still super effective at it.

5.56 does come up short in a lot of ways. But I think what it has going for it is that it doesn't score low in any category. There are several calibers that are better for specific task. But if you had to pick one to use in ANY situation, the 5.56 is basically the multitool of the firearm world.

Just like 9mm has been around forever, .223/5.56 will be as well. There are way too many 5.56 rifles in circulation to warrant the need to stop mass production of that caliber. Maybe years down the road another caliber will become more popular, but for now don't expect anything to change.

This conversation reminds me of the 6x45 NATO Program. Back in the 1990's I owned a Colt SP1 with 24" match barrel, A1 sights and flash hider and triangular A1 handguards. It shot great but I had to make brass from 5.56x45 and handload for it. Prices got crazy during the AWB and I sold it for $4300 and bought more 5.56x45 NATO ammunition and built a couple of nice accurate AR's and another car.

The Garand was originally designed to utilize the .276 Pederson in a 10 round enblock clip. This Cartridge predates the .276 British by over a decade for sure. This cartridge was 6.8 x 51 of lower pressure than the 3006 and required lubed ammunition which could be problematic.

5.56x45mm is a great round. Lightweight, controllable. Great attributes for a soldier. Professional and casual.

If I could get 5.56 in 77gr mk262 or 62gr M855a1 for a decent price, I'd never need anything else. As it stands, I rock a 20 inch A4 clone for the longer barrel (as I live in the country and need the extra velocity) and a 10.5 300blk for close/urban.

The 5.56 was adopted for its weight. We carried 210 rds as a basic load, which weighed 7 lbs. most of us carried 300+ rds on patrol.

556 is an all around amazing cartridge for varmint hunting great for defense against 2 legged varmints (not as deadly as a lot of other rounds but much more controllable and can hold more rounds). Perfect for war, if you can wound your enemy you take more then one man out of the fight (the one that was shot and those that need to get them to a doctor, you also use up the enemy’s resources to get the solider back to good health). That being said I like the 6.5 grendel even more and for all the same reasons

For the civilian it comes down to DOLLARS and CENTS. .223 at .50 cents a round or 6.8 SPC at $1.70 a round

During the 1960's there were some radical weapons intended to replace the M-14 rifle. The M16 was a temporary expedient. Reminds me--as late as 2009 I was using "temporary" buildings left over from the First World War, thrown up during 1917, in multiple states! The M16 has been a temporary expedient for almost sixty years now.

Keep 5.56 for close range. 6.8x51 and other full size cartridges are great for longer range. They are different tools. Keep them both available and use the 6.8 for DMRs.

Really enjoyed this, shooting my whole life, I love the 5.56 at 350 and in or so but I hate to think of it ice picking past 450-500 yards.... Instead of grabbing a 308, would love to just have a 6arc that can do it all well and out to 800

5.56 in the M4A1 will continue to have a place for support troops. And in that roll, it is perfect. It would in some respect take the place of the M1 Carbine from WWII. I can see I return to a bifurcation of arms where front line troops have 6.8x51mm NGSW and rear-echelon troops have 5.56x45mm M4A1s.

With the right ammo 556 is extremely deadly with the right ammo and plenty accurate. Mac just wants everything to be sub moa

“Sounds like your trying to hunt with an assault rifle…”. The whole conversation in a nut shell. The 5.56 is fine. DMRs have a purpose.

Most people who have never shot before do better qualifying than those who learned the wrong way

Thank you Gentlemen for this instructive and entertaining conversation. I've got to say I've particularly appreciated Pad's grounded attitude and perspective. As other commenter have pointed out, 5.56 was meant to be used out of a 20 inch barrel and provide light recoil, which it does ; being a one-size-fits-all is a big ask for any cartridge. Greetings from France. 👍

The 77 grain at 5.56 pressures was the refresh that the 5.56 needed to make it a bit more relevant. The 14.5" barrel on the M4 is what makes it irrelevant. Even extending the barrel to 16" and utilizing heavier bullets brings the 5.56 into the realm of 21st century reality. In Canada, we use the 20.5" C7 and the 16" C8. I believe these barrel lengths keep the 5.56 more relevant. Now, in the northern part of the country where I live, distance and range mean very little. Heavily wooded forests and extreme cold and large animals are the norm. Here, 7.62x39 makes more sense than any boutique cartridge. Many guys rushed out and bought 6.5 Creed's and have since dusted off their old .30-06's once again. Let's face it, is the modern battlefield a 1000 meter battlefield or is it an under 500 meter battlefield. If the battlefield remains close, then the 5.56 will fit the bill.

That whole jack of all trades master of none is so misused now days. It’s “A jack of all trades is a master of none, but oftentimes better than a master of one.” ~Viktor Vicsek

I’m a 300 blackout guy, and I replaced my 9mm with a 10mm as my sidearm. Stopping power is important when it really counts.

I have a 6 arc rifle and I love it, but I almost wish a rifle was designed from the ground up for it. My 16in barrel I would say performs on par or close to a 20in .243, based on velocities and bullet weights. The round is extremely efficient. However the bolt face is still a potential point of failure, an easily replaceable one, but the cartridge is limited to much lower pressures out of an ar-15 platform because of it. I would like to see SIG take the MCX line and develop a rifle and bolt face around the 6 arc using the 6.8X51 ammunition tech they developed. That would be a screamer, with much lower recoil capable of the high pressure performance, but lighter in weight and recoil.

This was a terrific studio debate/discourse. I would love to see this as a template to try/eval a platform, cartridge, etc w/ guest or 2 (review even) - heck, you could put out survey questions about what the viewers would like to see covered.

One of the best attributes of the AR15 platform is it's modularity, a new caliber is as simple as swap the barrel and the bolt or upper and you're good to go. That's why my AR15's are 5.56/.300 Blackout/6.5 Grendel ............. long live the 5.56.

Two factors that should be addressed: 1) A larger caliber reduces the amount of ammo troops can carry by one third. Accuracy becomes important with an underpowered round, like the 5.56, but it becomes more important when you carry fewer rounds. 2) A larger caliber rifle will be substantially heavier, like the spearhead. Does transitioning to a heavier rifle make sense at a time when physical fitness standards are being effectively lowered?

Jason and Pat, thank you for your service. MAC, thank you for bringing meaningful content to the masses.

Whatever changes are made to military ammo, change the weight of the Soldier's load. Bigger, heavier cartridge equals heavier load. You end up with diminishing returns. If military planners think that Afghanistan is going to be the norm - they should change the rifle round. If not, keep the 5.56. If the enemy is exchanging rounds with you at 800m - call in artillery on their position.

5.56 is very efficient,lots of energy for a little powder,one of the best ever and still holds its own.

For many Americans, myself included, we don't have 5.56 because it's a superior cartridge, we have it because of availability. If Big Army switches to 6 or 6.8 many Americans will follow suit because of that. 5.56 is sufficient for many tasks and is very comfortable and controllable. For those reasons it would be a very LONG time before it goes away. A 6mm or 6.8 that has similar qualities would be an even better cartridge overall, but Americans buy what the Army shoots. For these changes to be common in the civilian market the military almost HAS to change first.

we've been effectively using .223 handloads in 18" & 20" barrels out to 500yds. for years to deal w/ coyotes. Any barrel length shorter than 18" reduces the effective range / BC on that caliber. 6.8 SPC or 6.8 Rem is an excellent cartridge , but so is Wilson Combat's 300 HAM'R problem both are in short supply & therefore expensive in comparison.

The Vietnam Vets I have spoken with came up against far more SKS rifles , than AK's . .556 was designed to be utilized in a 20 inch barreled AR . Lately it seems as if shorter barrels are being used more and more and there is an obvious down side to this. As for me , I am partial to an 18 or 20 inch barreled rifle with 1 in 8 twist along with heavier bullet weights for stability.

The 6.5 mm Grendel stays supersonic all the way out to 1,000 meters just what the doctor ordered for combat operations in Afghanistan.

5.56 persists because it's cheaper to keep her and at the scale we're talking about, it's really, really cheap. I'm most interested in 6mm ARC as a relatively inexpensive replacement that truly increases effectiveness. It doesn't change the magazine and works neatly within the operating parameters of the guns that already use 5.56 and it offers tangible improvements in range without sacrificing terminal effect at any range or soft shooting or anything like that. Get new barrels or barreled uppers and bolts and let the quartermasters do what they do. If you're OK with the marginal expense of all new guns, which is what you're looking at when you look beyond the STANAG magazine, like the US military seems to be with the XM5, I think that opens some much more interesting doors.

5.56 and 7.62x39 will always be here and always will remain relevant.

I think with each advancement in small arms ammunition, we are seeing the effects of diminished returns. Yes there are superior calibers ballistically and logistically but for the civilian market, cost is of even greater importance. How many dudes are willing to move to a new platform or chamber with a 200% increase in Ammo cost but only a 19%-23% increase in ballistic performance? Considering in civillian life, justifying lethal force against an aggressor gets harder the further you move away from 55 yards.

He keeps saying Stoner's design was around the 5.56. It was not! It was around the 7.62x51. He was forced to downsize to 5.56. But it was not what Stoner originally envisioned. The AR-10 was!

I have always thought that the 6mm rem. was the perfect military round. 100 gr. projectile @ 3,000fps. Best of both worlds. The problem has always been the military has to re-invent the wheel Every time !

Interesting conversation. What I particularly liked was the willingness to tolerate different points of view. Thank you!

I'm only 10 minutes in, but I think the important thing to think about is WHERE we expect to be fighting the next pointless ground war thats going to get thousands of young men killed for no reason, the terrain, climate, etc are very relevant as to whether 5.56 is "good enough" or not

As someone who lives in middle of nowhere not far from Mexican Border, I use 5.56 due to necessities of availability & cost. Makes me very nervous that the US Army flirting with making 6.8 universal cartridge. Because down the road, it will have impact on 5.56 availability & price in civilian market

I’m all for 6mm ARC. However, the 5.56 is still a serviceable cartridge for general use in a militia context. It’s plentiful and works good enough. Changing to a new round, though it sounds easy, has quite a few supply/logistics hurdles to overcome.

My take away from this discussion is that they seem to be forgetting what the M16 and the 5.56 was designed to do in the first place it is an assault rifle and it does that job very well and therefore it is not a sniper rifle nor is it a designated Marksman rifle. The same problem occurred during the global war on terror when Special Forces operators where firing thousands of rounds through the M4 on full auto trying to turn it into a squad automatic weapon. The problem I feel is that too many people are trying to make this weapon system do something that it was never intended to do, now that being said you can modernize the AR-15 M16 you can swap calibers around and make it fill different roles however at the end of the day this cartridge and the rifle that fires it were designed together to be an assault rifle and therefore it shines within its design parameters. It's only when you try to press it into a role that it wasn't designed for that you realize it has shortcomings that is not a fault of the design instead in my opinion that is a result of the end-user trying to make do something it was never going to be able to do, remember the a10 warthog it's a amazing attack aircraft what it is not is an amazing fighter jet.

I plan to upgrade to 277 SIG FURY because I hate myself, hate barrels, and hate my wallet.

Love it. Light, good ballistics, fast and great distance.

MAC, this video is awesome! Please do more videos like this on 2A issues/concerns with a similar(if not the same) three-member panel for an objective discussion covering all the pros and cons of the issue at hand. In regards to this video’s subject matter, everyone made very valid points and it was an outstanding conversation. In my opinion(and we all know what opinions are like and why they are like that😉) I think the military procurement process and the politics surrounding it are so much of a huge bureaucratic monster with lots at stake in regards to funding, contracts, and votes that they don’t want to upset the apple cart. Although there might be something better, what they are using works good enough for most situations. The logistics of supplying it, training with it, and using it have been well-ironed out and it works. A new round, barrel, bolt, and magazines being issued to hundreds of thousands of service members would be costly. Not to mention the new training and tooling it would require. Again, Special Forces have their own budgets to accommodate for their mission requirements. Firearms manufacturers sometimes get contracted to custom make firearms for the SF teams. But you’re talking about very small teams as opposed to the hundreds of thousands of regular military personnel. As far as the political concerns, I’m sure there are members of Congress who have contracts in their districts who don’t want things to be altered or questioned. If the military did decide to go with the 6.8 ARC some firearms manufacturers may try to bring a lawsuit alleging that the military is adopting a new service rifle without having an open competition. There was controversy about the M-16 to the M4 about it being a different firearm for standard issue. Yet it has lots of parts commonality and shoots the same caliber. But if there is a new caliber requiring a new bolt, new magazines, and new tooling to provide it, the competing manufacturers would cite this and could possibly win the case. So, in the interest of keeping everyone happy and not causing a major fuss, the military would rather use a caliber that might be slightly inferior to others that works for nearly all of the military for most situations.

I agree the 6 Arc just makes since. I'm a Vietnam era Air Force vet who qualifed with an M-16, fell in love with that rifle the minute I shot it. I grew up a hunter and shot 222 for groundhogs and 30-06 for deer. I liked it so much when I discharged I bought a Colt H-bar. After punching holes in dirt and paper it sat in the closet for 20 years before I sold it. Years later, after it became Americas pet firearm, I wanted one again. I won one at my gun club, decided to freefloat it, change the handguard and grip to Magpul, and put in a Geissele 2-stage trigger. After that I thought I would like to build my own from scratch. Now I have 8 Ar's of my own and have built several more for other people, I'm hooked.Of my builds 4 are 556 or 223 Wilde, two are pistol builds, 1, 9mm pistol build, 1- 350 Legend, 1- 7.62x39, and my last, which I have not shot yet a 6mm Arc, can't wait to send some rounds down range. I think the weight savings and having most everybody with the same ammo is a nobrainer, and having everyone with a rifle capable of doing a better job even if they are not up to the long distance job. But they could be trained.

Great exchange of knowledge on various platforms. Learned a lot and took away the fact that various parts of our military units have different types of platform use based on the task.

i personally have a 556, 6.5 Grendel and built a 6m/m arc sept. in 2020 not going to push my 556 to the side( to much ammo) 6.5 grendel came about because my neighbor was a navy seal and they were using 6.5 grendel and they loved them over the 556 6m/m arc wanted a little more from the small case and read about the contract hornady got from the military to work up a new cartridge for the AR platform. liked it and had to build one

#1 benefit to 5.56 - soldiers don't run out of ammo as often, and that is paramount

Where the mistake was made was when we got away from a 20" barrel and we got away from the rifle twist for the M-193 ammo. The M-16 itself is still a viable platform if wasn't shortened up and castrating it.

You need to look at this from the perspective of a comity of officers tasked with a cost/effect analyses of the ammunition. They do not hold effectiveness to the highest of needs when selecting any gear but rather a mix of effect, cost, and easy of procurement. If the ammo works really well but is extremely expensive which means you can't afford to get the numbers of it you need on a mass scale. This entire scenario is the main reason the military is so slow to adopt anything let alone adopt something to replace something that is still very functional and at low cost. I think we would see plastic cased ammo become the standard before you see the 5.56 get replaced given how well it works against humans in combat.

Good enough is the enemy of perfection. Perfection is the enemy of a balanced budget.

Four Guns is my local gun shop, I have never been so pumped to see a hoodie before.

Enjoyed the discussion and really provokes thought on future planning. I’m really impressed with Pad’s contribution to the discussion and the demeanor with which he presents it. Kudos on finding this young man and sharing the platform with similar mindsets yet a different PoV.

I think 6 arc and 6.5 Grendel would be a lot better combat cartridge

In my opinion the 6mm arc or even the 6.8 would finalize the debate once and for all of what is the perfect military round.I am not a military guy but I've always thought the 5.56 was a wee bit small.I also agree that if the military adapted either round then the public would be right behind them!!!

Fascinating discussion. I think this 6.8x51 winds up being used in specialized units, and the M4/M16/5.56 is going to serve for another 10-15 years at least. 6.8SPC would be better in a general purpose rifle, but not better enough to make the change. No effing way the 6.8x51/277 Fury winds up being the standard issue rifle.

Price, availability, and the amount of platforms that use .556 over various manufacturers make this a moot point.

When the role of the infantry today is to suppress tiny heat miraged silhouettes at 600-800+ meters long enough to call in air support, the difference of whether or not they're missing all those shots with 5.56 or 6mm ARC makes little difference to a military bean counter.

Great conversation gentlemen. Thanks enlightening. Good Fortune Great Success.

I used to use alll kinds of different calibers for hogs and deer. 30-30,30-06, 280,270,8mm Mauser and 12 gauge slug. I got rid of everything and went with low recoil. 5.56 for hogs and 350 Legend for deer. They both use the same lower in AR - 15. If you can't hit a squirrel at 100 yds with an AR, you may need to practice more. Come to Texas and learn to shoot.

5.56 is great, you just need that 18-20" of barrel. All this 16" carbine stuff gives up so much in velocity that no one seems to talk about. 300-400 yards is no problem with a proper length M16 and ball ammo.

5.56 is good for engagements within 300 yards that is standard engagement distance. The NGSW look like they are gonna equip the US army to fight in Afghanistan.

The Close Combat folks do almost all of the combat shooting. The majority of the force are basically carrying a rifle for self defense. What has evolved is the shooters get the M7 very high end rifle while the support folks get the M16. Some folks don’t even get a rifle. IMO this high low mix is good. The shooters get the expensive best tool to kill the Bad Guys.

I'd be interested in a follow-up now that Sig and that oddball cartridge is the official NGSW. I agree that there are better alternatives that are currently available, but until the military does away with 5.56 it's going to be a mainstay. Honestly, part of the problem is how long its been around and how much has been stockpiled both by civilian and other NATO countries. 5.56 isn't really the best choice for anything, but it's not going away any time soon.

I wasn’t sure where this video was going to go but it was definitely worth the time! I’ll take a higher BC all day long especially when you’re just looking at a barrel swap?! Accuracy is EVERYTHING! Thanks y’all!

7.62x54R is a real man's cartridge, steel wood and fire is all you need

Knowing how much stockpiled 5.56 ammo is out there in the civilian world, especially on ranches and farms, I truly doubt the AR-15 is going away anytime soon. Personally, I have a couple twenty inch S&W Performance Center AR-15's and love the rifles. They are very accurate shooters.

I used the M16, and the M9 all my military career and that's pretty much what I use without any problems with them. I will not pass judgment on the 6.8 ARC until I have some range time with it. I have used my AR10 and loved it, I've always wished the Army would've gone that way but no I'm not that lucky. I'm kind of an old Army guy because I love my M1 Garand, M14, and my 1911s. In fact, my daily carry is a 45ACP.

Excellent discussion! I'd love to see more like this.

I really enjoyed that philosophical conversation. Three educated perspectives; I learned some stuff. Thanks.

something like a 6x45 would be more likely to get widely adopted over the 6 arc as far as universally issued. that is just a barrel change

What a great fking conversation. Thank you gentlemen. It will be interesting to see what happens. Great points made.

For the facts on the development of the 5.56 and the AR platform go watch "In Range TV"s video: "What would Stoner do - In his own words" The 5.56 was developed to work with a conscript army, carrying large amounts of ammunition in adverse conditions where ranges were short and snap shots or suppressive fire were the norm.

According to Wikipedia 6ARC is a necked down 6.5 Grendel case to 6mm. (please correct me if I'm wrong) At 17:57 min. Tim says that 6.5 Grendel isn't a good cardrige for AR platforms because the Grendel doesn't fit well in STANAG magazines. If the Grendel case is the parent case of 6ARC there should be the same problems with 6ARC or not???

Im glad he mentioned the short barrled 556s are a joke. They are for sure. The 16 inch bare minimum anything less is dumb. Short barreled 300BO ok

Make the standard 5.56 round in country some variation of a 69-77 grain projectile. When the Marine Corps switched from the M16A1 to the A2, rifle scores across the board went up a few points. When they switched from 55 grain to 62 grain, the scores went up again. Though the M855 62 gr projectile is inferior in many ways to 55gr M193, the weight and better ballistics of the 62 grain allowed it to carry better at the 500 yard line. The shooters at Camp Perry every year take the AR-15 out to 600 yards and shoot MOA accuracy using mainly 75-80 grain OTM projectiles. Many loads are loaded to an OAL that will not fit in a standard magazine, but the point still stands. There is definitely more potential in the 5.56 and it would be far more logistically feasible to upgrade the projectile than the entire cartridge.

The 5.56 has always been less than ideal. But, it appears, based on the fact that it is still here, after 60 years of service, that it is a combination that almost everyone can shoot very well and very quickly. In addition, you can definitely carry a lot more ammo than larger more capable cartridges like the 6.5 CM. I do think they should go back to the 20 inch barrels. I personally loved the rifle that I was issued. It was not a sniper rifle, but it was plenty accurate for its intended purpose. It was very light and the ergonomics are great. I doubt it’s going to change anytime soon.

I want something with light recoil, 1000 yard effectiveness, sub moa accuracy, ability to defeat modern body armor, doesn’t lose magazine capacity, inexpensive and readily available. I want all of this without making any sacrifices.

Keep in mind that the 5.56 was designed for the M-16 with a 20" barrel. The current M-4's that are in use are for close in, urban fighting, whereas the M-16 was intended for open battlefields. Any discussion about the effectiveness of the 5.56 has to take this into account. Other than how they operate, M-16's and M-4's are different weapons with different missions.

I am not a 5.56 fan, because my time of service is M-1 Garand and M-14 rifles. As a Marine we were trained to shoot these weapons accurately consistently. The size of man was not a factor until the man was under 5 feet 6 inches. The Arvin carried the M-1 Garand and functioned well with it while they had it. They liked the M-16 after the change in ammo came out because they were smaller people. Troops that carried the M-16 after corrections made loved the weapon in the Jungle combat and or close combat they experienced. I had no issues firing either the M-1 or the M-14 and as a civilian that owned an AR-15 chambered in the 5.56 did not like it at all. Carrying large quantities of .308 ammo or 30_06 was indeed a chore, but most of managed very well.

In combat, you have to think about how the enemy fights. No one stands in the middle of the open shooting, so largely what you are doing is suppressing, even as the main line infantry.

5% of the Military are trigger pullers, the other 95% don't engage directly in combat, but still need a rifle when things invariably go wrong. Zero to 300 meters is still going to account for 90% of all rifle/carbine engagements. What matters is whether the cartridge can do its job within that envelope, not whether it helps you get better hits at 600 meters. Once the 5.56 can no longer reliably kill or wound within 300 meters, it will need to be replaced. Modern Body Armor that can defeat 5.56 ball that is in near universal use, will necessitate a caliber change, nothing else. SIG and the Army are 100% on the wrong track, producing weapons that "do it all", based on the last wars the U.S. engaged in, not future conflicts. All of the alternative cartridges discussed aren't going to do anything for the military that the 5.56 isn't already doing. Regarding the AR/M4 platform, most of the issues have been worked out and if you are issued a 14.5" 5.56 NATO 1:7 USASOC Improved Upper with a quality optic and MK262 ammo (not the M855/A1 shit), you're probably going to be more than OK in 2022. The M16/M4 has only a few unresolved issued that are minor for big army; magazines literally freezing inside the magwell in the Arctic, gas tubes blowing-up if water is in the barrel and that's about it.

I buy 25 round mags for my 6.5 grendel and they feed just fine. These mags are not radically curved. They look so much like my 5.56 mags that I intentionally buy the grendal mags in FDE and my 55.6 mags in black so I can easily tell the difference.

Most enlightening convo I've heard in YEARS. Thanks guys.

I’m really digging this gun podcast. Please do more of these

The strengths you're mentioning of the other rounds just don't weigh heavily in the combat environments the military has operated in for the last few decades. The typical infantryman doesn't need to hit prairie dog size targets, at long range, in high wind. While 5.56 may not be the greatest round ever made, it's been very effective for what we need it to do and there's no pressing need to change it.

What a GREAT, GREAT conversation guys...GOOD STUFF! I think the AR-platform is here to stay in one way or another and that it is adaptable enough to undergo changes as gradually or as quickly as desired. We, in the U.S. Army (mid-'70,s) were issued M-16 A1's which I QUICKLY fell in love with! However, I never liked the charging handle arrangement or the (to me, at least) seemingly weak-looking area where the stock/buffer tube meets the lower receiver. I would like to see the rifle modified to be charged without interfering with the "cheek-weld" and current sight picture of the user. Too, strengthen that stock/receiver junction without changing over completely to an ACR or SCAR-like rifle! I really believe that between GAS and MASS tuning the AR can accomodate most any cartridge/caliber change. What I'd REALLY like to see is for a new propellant to be developed that would work with a higher B.C. bullet and increased mass or caliber based on the .223 Rem./ 5.56x45mm case. Maybe an enhanced .277 Wolverine something or other.

It aint broke, don't fix it. If you want MOA accuracy with a little more horsepower mix in some AR10's at the squad level.