.308 vs .223/5.56 Carbine Arguement

[Sherman]

Hey all, I had a guy tell me not long ago that carbine length 308 gas guns are pointless. He was saying that shorter barreled 308's dont make as much energy as does a 5.56 rifle of the same length, say 14.5" His arguement was that at that barrel length the 308 doesn't effectively use all the powder to propell the round, basically that it all burns outside the barrel as muzzle flash so it's velocity is substantially lowered, and that 5.56 is essentially more effective in short or shorter barreled setups.

I'm curious if anyone has any real world data, experience, whatever, on the issue. I personally think his arguement is crap, I dont see how the 5.56 could have anywhere near the energy of the 308, even in a short barrel setup. What do you think?

 

[JimGnitecki]

Re: .308 vs .223/5.56 Carbine Arguement

The raw numbers are so different for 308 and 5.56 as to make his argument patently silly.

Sounds like a guy trying to justify his selection of a 5.56 versus a 308.

Jim G

 

[KYpatriot]

Re: .308 vs .223/5.56 Carbine Arguement

Yeah, not even close. But the 556 is still way better than a handgun. Well, most handguns...

 

[Sherman]

Re: .308 vs .223/5.56 Carbine Arguement

I agree, I dont think it's even remotely conceivable that 5.56 could hang with 308. Does anybody have any chrono results for 308 out of a short rifle?

 

[KillShot]

Re: .308 vs .223/5.56 Carbine Arguement

In my opinion, the .308 is the best all-in-one round because it provides plenty of power for punching through barriers up close and with the heavier grain projectiles, it's good out to 800-1000yds. The 5.56 in no way compares to a .308. In fact, I think the only advantage the 5.56 has is being able to carry more ammo than if you were carrying a .308.

Just my .02.

 

[kraigWY]

Re: .308 vs .223/5.56 Carbine Arguement

Just some numbers of stuff I have on the computer where I ran through a chrony

16 inch 308, 180 grn Rem. Factory ammo.

Vel 2552 KE 2603

And some 64 grn Speer LE, out of a 20" AR

Vel 2850 KE 1154

Not sceintific but close enough to say THAT DOG DON'T HUNT.

 

[Solid_Squirrel]

Re: .308 vs .223/5.56 Carbine Arguement

From what I can tell, searching and playing with an energy calculator, with both the 5.56 and 7.62 NATO having 14.5" barrels, the 7.62 NATO will still be producing approximately 1000 ft/lbs greater energy than the 5.56, with both shooting (close to?) their optimum loads for energy. I don't think it's true at any barrel length.

 

[BCP]

Re: .308 vs .223/5.56 Carbine Arguement

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sherman</div><div class="ubbcode-body">I agree, I dont think it's even remotely conceivable that 5.56 could hang with 308. Does anybody have any chrono results for 308 out of a short rifle? </div></div>

My 16" fulton barrel maxes out just under 2500 fps with 175smk and varget.

There aren't any "carbine" calibers I can think of that will "beat" a 308 it's just such a thumper.

 

[Sherman]

Re: .308 vs .223/5.56 Carbine Arguement

Thanks for the info guys, basically confirmed what I was already sure was true. My buddy is just one of those guys that hears something somewhere and believes it to be true regardless of what anyone tells him.

 

[Solid_Squirrel]

Re: .308 vs .223/5.56 Carbine Arguement

There doesn't seem to be even a kernel of truth to it, even with the most generous interpretation.

 

[RictusGrin]

Re: .308 vs .223/5.56 Carbine Arguement

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Solid_Squirrel</div><div class="ubbcode-body">There doesn't seem to be even a kernel of truth to it, even with the most generous interpretation. </div></div>

Sure it does.

My 16" Noveske runs M118LR at 2490 fps. My Mk.11 (20") runs the same ammunition at 2520 fps. So, it would seem that the little carbine does just fine, and since I shoot it to 1K yards without any issues I'm a believer.

As for the 5.56mm, my Mk.12 is .5 MOA flatter at 800m with Mk.262 than my Jr.'s M110 with M118LR and in my SPR clone I shoot 77 gr. handloads at 2800 fps to 1K yards with good results. I've even done it on a maiden at 1K meters just to prove a point, getting two traces in the air and two hits using M855 in a Mk.12. The first shot was a spotter and was just off the edge.

Both cartridges will do the job, even the .308 in a carbine.

 

[Solid_Squirrel]

Re: .308 vs .223/5.56 Carbine Arguement

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RictusGrin</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Solid_Squirrel</div><div class="ubbcode-body">There doesn't seem to be even a kernel of truth to it, even with the most generous interpretation. </div></div>

Sure it does.

My 16" Noveske runs M118LR at 2490 fps. My Mk.11 (20") runs the same ammunition at 2520 fps. So, it would seem that the little carbine does just fine, and since I shoot it to 1K yards without any issues I'm a believer.

As for the 5.56mm, my Mk.12 is .5 MOA flatter at 800m with Mk.262 than my Jr.'s M110 with M118LR and in my SPR clone I shoot 77 gr. handloads at 2800 fps to 1K yards with good results. I've even done it on a maiden at 1K meters just to prove a point, getting two traces in the air and two hits using M855 in a Mk.12. The first shot was a spotter and was just off the edge.

Both cartridges will do the job, even the .308 in a carbine. </div></div>

I think I may have phrased that ambiguously, as I don't disagree. I meant that there does not seem to be any truth to the claim that when you reduce the barrel length of both a 5.56 and 7.62 NATO to 14.5", that the huge advantage for the 7.62, speaking strictly about energy only, is somehow diminished to the point of making it moot. It isn't. Even with both having short barrels, the 7.62 still produces way more muzzle energy.

 

[Nimzoblanca]

Re: .308 vs .223/5.56 Carbine Arguement

Out of my 16" bbl FAL, I get the following chrono numbers with NATO headstamp military ammo:

147g British Radway Green - 2645 fps (2284 ft-lbs)
147g Portugese FNM - 2600 fps with one batch, 2540 with another batch (2100-2200 ft-lbs)
146g South African - 2533 fps (2081 ft-lbs)

With 5.56 M193 out of my 16" AR15 at about 3150 fps giving roughly 1200 ft-lbs energy, I'd say the guy stating that 308 short-barrel guns are pointless doesn't know squat.

 

[jakerz3]

Re: .308 vs .223/5.56 Carbine Arguement

223 is cheaper to shoot in a carbine. Which is better for my cheap a$$.

30 cal get's the bolt gun nod from me. Can't afford having the option to sling out 20 rounds of 308. I would empty it every time... I'll stick to just 5 at a time. My wallet stays a little fatter that way.

Pure performance only... 308 wins in just about every department. Except, like killshot said, weight of the ammo. Which would only come into play on a LBV.

 

[I Am Hero]

Re: .308 vs .223/5.56 Carbine Arguement

16" carbine .308s are awesome guns! They have a lot of pop and a lot more umph to them than a 5.56 in from my experience. I have never run the numbers but just shooting a different objects as targets suggests to me the .308 has all the pop it needs in a 16". I prefer the 20"+ for the .308 because I like long range shooting better than carbine style shooting but there is nothing wrong with a 16". If that was a big problem, I don't think you would see the availability from the producers that you do see.

 

[bmt]

Re: .308 vs .223/5.56 Carbine Arguement

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sherman</div><div class="ubbcode-body">I agree, I dont think it's even remotely conceivable that 5.56 could hang with 308. Does anybody have any chrono results for 308 out of a short rifle? </div></div>

My 16" fulton barrel maxes out just under 2500 fps with 175smk and varget.

There aren't any "carbine" calibers I can think of that will "beat" a 308 it's just such a thumper. </div></div>

My DPSM 306 carbine generates similar ballistics.

Essentially hitting a touch harder than a 303 British.

As Clint Smith says: One million Nazis can't be wrong.

Canadians have also killed million or so Moose with the 303 round.

BMT

 

[Rovieairto]

Re: .308 vs .223/5.56 Carbine Arguement

That is a north American gun wanker.
It's natural tendencies are to give bullshit advice.
It may get angry if you try to teach it anything, so don't.
Just nod and smile, but don't learn from it.

Funny that he picked these two calibers to compare because their expansion ratios are near identical if barrel length is held as a constant.
This means that they should extract a similar percentage of energy from a grain of powder.
The 308 does get a little MORE energy from a grain of powder than the 223 in the same barrel length, but the velocities are usually lower.
This makes it more efficient if anything.