What is next chambering after 5.56 that has enough oomph

[bushmaster1313]

Lots of folk talk about the .5.56 being under powered, especially against Afghan mud walls.

Would .243 or .257 Roberts do the job?

What is the next round up for putting down the hurt.

 

[Mike in Reedley]

For the good guys it's easy, .308 (7.62x51 m/m), 300 Win Mag then JMB's baby, Ma Duce. If available, C130 Spectre 30 m/m or 105 m/m streams of justice helps them meet up with potential virgin dates on Allah-only.com.

 

[TANKLEGACY]

AR10 (308)

 

[bushmaster1313]

No in between 5.56 and .308?

 

[TANKLEGACY]

There's is...but why?

223/556 on left, 308 on right

 

[ameridaddy]

Maybe 300 Blackout, loaded similar to AK-47 (7.62x39) levels, if you want to use an AR platform. Still shooting a 7.62 (.308) bullet as the previous posters recommended, but only about 123 gr instead of ~150 gr.

 

[amazingflapjack]

well, there it is..

There's is...but why?

223/556 on left, 308 on right

A picture is worth pages of blather that means nothing.

 

[Double-O-Dave]

In my opinion, the next step up from the 5.56mm is the 6.8mm SPC. It was designed from the beginning to fill the gap between the 5.56mm and 7.62mm (.308 Winchester). If you look at the ballistics charts for the 5.56, 6.8 and 7.62, you will see that the 6.8 does indeed fall halfway between the 5.56 and 7.62. Many people think of the 6.8 as the .270 in the AR world. If you already have an AR chambered in 5.56mm and you want to shoot 6.8mm, you will need a 6.8 upper with the bolt (you can use the charging handle from your 5.56 upper), and 6.8 SPC magazines.

There are a lot of .300 Blackout fans also, and one advantage of the .300 is you only need the upper, and you can use the existing charging handle, bolt and magazines from you 5.56mm AR.

I put together my 6.8 SPC last year (Palmetto State Armory upper and lower), but haven't taken any game with it yet.

Regards,

Dave

2/25/17: photos of my PSA 6.8 SPC II rifle.

Dave

 

[Mike in Reedley]

You might sneak a privately owned handgun in if you're in the right spot in the food chain, or a pilot, or SF. I don't think you'll be able to sneak in granddad's old 257 Roberts deer rifle to prevent goat molestation though.

 

[Biggfoot44]

The *next* chambering up would be the 6x45 .

 

[Nevada Ed]

If you are talking GI issue ammo the 308 is next in line.

Don't expect a GI to pull a 257 Roberts out of his pocket to get
you out of a jam !!

Now if you are just asking.................
try this.

 

[Mack]

Doubtful anything less than .50 cal will penetrate an Afghan mud wall at other than point blank range.

 

[Bozz10mm]

Doubtful anything less than .50 cal will penetrate an Afghan mud wall at other than point blank range.

Exactly what I was thinking. How do we know .308 would even do it. Launch an M203 round at it and then fire away with 5.56.

 

[Arik]

That isn't just mud. It's mud, straw, stone, clay and timber. Those walls are thick. You're not getting 7.62NATO through it. At least not from any distance.

Check out the thickness of the walls. Earth is very good at stopping bullets. Which is why everyone uses sandbags

Here is a video of clay bricks just stacked together in a form of a wall. There is no mortar, no mud, no straw or timber. They are dry clay bricks and the thickness of the "wall" is the length of one clay brick. Guys look like they are 25 - 50 yards away. Out of 20 AK rounds one managed to get through a seem but there was no damage to the other side. 4 rounds of 45-70 only made a dent.

The Compressed Earth Block Bullet Proof Test - YouTube

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[DWalt]

The 6.8mm SPC would be the logical next step in the AR action for military use. Basically a shortened and necked down version of the .30 Remington. I was testing the AR-15 platform in 6.8mm before most people even knew about it and was very impressed. I still have a box of the first lot of 6.8mm ammo that Remington made. Some feel the 6.5 Grendel is in the same class, if not superior.

 

[Biggfoot44]

As a pure long range/ hunting ctg, the 6.5Grendel is superior.

But people who know more about such things than I, have explained at length why the 6.8SPC is better suited to belt fed. Meaning suitable for upgraded SAW ( or similar weapon) , and hence preferable as a Mil ctg.

 

[Tom S.]

There are a lot of .300 Blackout fans also, and one advantage of the .300 is you only need the upper, and you can use the existing charging handle, bolt and magazines from you 5.56mm AR.

There are a lot of Blackout fans, but for the life of me, I can't figure out why, other than as you said, it fits in the mag well. Ballistically, it's pretty underwhelming, especially in it's original form as the 300 Whisper, which was designed to be used at subsonic levels in a suppressed rifle, for which it's a decent idea. Past that, this writer from All Outdoors sums it up pretty well:

The high velocity 300 Blackout round is still short of performance compared many similar sized rounds. In fact, compared to the old 30-30 lever action round, the 7.62×39 AK round, or even the .223 68-77gr rounds, the 300 Blackout falls short from a ballistics and energy perspective.

My problem is that once you drop the bullet weight to gain enough powder to make the 300 Blackout supersonic/high-velocity so that it will actually cycle in your average AR-15, you gain nothing over the .223 round. In fact at the 300-yard mark your typical 68-77 gr .223 round will be delivering more energy than that 300-Blackout/Whisper round, and at the muzzle they are nearly identical.

The .223 has proven itself to be an excellent soft target stopper without overpenetration. On steel and thick-hided hogs, the Blackout seems like a winner, but in most other cases the 300 has shown to be a consistently and severely over-penetrating round. There is no way I would risk using the 300 Blackout for home defense. That is perfect for thick skinned hogs at close distances, but not so great for anything else unless you are shooting through barriers–but then again the 7.62×39 AK round is still a better option and far far less expensive.

The 6.8mm has better stats, but I still went with a 308. Everything about the round is easier to find, even in outer Mongolia.

 

[DWalt]

It's highly unlikely there will be any change by the U.S. military away from the 5.56mm as its official caliber, at least for the next several decades. There's far too much investment already tied up into 5.56mm ammunition and weapons to abandon it. In banking terms, it's too big to fail. The 6.8mm SPC is clearly superior to the 5.56 in the AR platform, but that is essentially meaningless to the military (except for possibly SO use). The 5.56 does the job they want done for an infantry rifle, and that's that.

 

[elm_creek_smith]

Knock, knock!

Bet they'll open the door next time!

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[Groo01]

Groo here
The next would be based on the 556 case.
The .25-45 sharps fills the bill.
It will take up to 100gr bullets,25cal,feed through the AR mags, only require a barrel change.