.223 vs 5.56 (yes Rob this means you and other pros)

[fightingquaker13]

Generally I don't get into arguments over ammo. X grain over Y grain, or brand A over brand B unless someone gives a good reason. For instance, I have been persuaded that 124 grains are generally better than 147 grain rounds in 9mm. Here though, I ask an honest question. My 5.56 DPMS AR will cheerfully shoot 55 grain .223 el cheapo Remington hollow points. The accuracy is good. Clover leaf at ten yards, and desert plate at 100 with an eotech, shooting off hand. That's good enough for me. Based on only 150 rounds fired, the ammo also seems relatively clean. The question is whether I'm losing anything ballistically with the weaker .223 over the 5.56? I only have a hundred yard range. If I need to push it to 200, 300 or, just to annoy the bad guy, 400 yards am I losing anything? Also, has anyone had a problem with the cheap Remington .223?
Thanks
FQ13

[GUNS-R-US]

FQ I use the cheapest ammo I can find for the range generally 55gr stuff, but for my Defense load around the house I use the TAP 40gr. for less penetration. If I were concerned with the longer range shooting I would look for 62gr ammo. Of course what your rifle will use best depends a lot on your twist rate. Generally the heavier the better for long range performance, but if you don't have the right twist rate for it you won't get right performance from them. Even the 55gr ammo will work for 200-300 yard shooting in a pinch. At least that's my .02 worth! 

[usmcdadx2]

FQ, I’m not a pro by any anybody’s stretch of imagination. But my 5.56 DPMS Lo-Pro with a 1 in 9 twist has done the job with everything I’ve run through it from the cheapest bulk .223 and 5.56 rounds I’ve found to some really hot .223, 77 grain handloads a “varminter” buddy gave me to try. Not to mention some of the nastiest looking surplus ammo I’ve ever seen. I’ve used bullet weights from 40 to 77 grains, FMJ and HP. I have been able to ring a 10 inch steel plate at the 300 yard line with all of them except the handloads and the 40 grain TAP ammo. The worst 100 yard group I’ve ever had was the handloads which came in at just over 6 inches. I’m guessing this round would have been better with a different twist rate. The TAP ammo was the next worst but is super tight at 50 yards or less. The ammo that groups best for me is either the PMC Bronze in .223 or the American Eagle Tactical in 5.56. both 55 grain FMJ.
Like GUNS R US my home defense load is the TAP round but for the range I’ll shoot anything I can get at the right price.

[BAC]

I don't think FQ was asking about bullet weight, but what he'd be losing by using .223 vs. 5.56 in his AR.  Since I haven't used an M16/AR15 since the mid '80s, I can't help with the answer, only the question.   

[Fatman]

search for ballistics tables on 223 and 556. Should be plenty on the net.

[Sponsor]

[m25operator]

The ballistics on .223 vs 5.56 is nearly identical with every weight of bullet, should be hardly any difference other than your personal rifles likes and dislikes, the main difference is chamber pressure using 5.56 in a .223 chambered rifle, and that really has not been a problem in a while, the industry recognized the problem and made a safe chamber in between on AR's, any way.
On AR's, I do like to try different weights and manufacturers, and find a good commercial or surplus load that is accurate and available, I don't want to handload this ammo, except for a match gun, all others need to be able to shoot accurate 1 - 2 MOA, with something I can buy and sack away. Do try the 77gr, stuff, in your 1in7 twist guns, might surprise you, at the longer distances, 50 yds and under, unless its a real loser, will probably do head shots all day long. Inside the house or yard, all will probably do very well, the type of bullet is a concern for safety and not much else, but worthy of research.

[twyacht]

Check this out FQ, it wouldn't let me paste.

http://www.thegunzone.com/556v223.html

To summarize, SAAMI pressures are different, throat and leade dimensions are different, but your splitting millimeters, the muzzle velocity is consistent but varies from rifle to rifle, barrel length, twist rate, etc,...

For SD, a Wally World .223, vs. a Lake City M193, will make no difference at 7-10 yds. It will go right through, PERIOD. check the reality the over penetrating is going to happen, (that's why a 12g is such a viable option)....

Either way, as posted, the Hornady TAP, is a lighter bullet, ergo faster, but will cause a tremendous wound channel and literally explode in soft tissue, vs a heavier bullet that will retain more mass as it passes through.



P.S. Whatever m25 said,...

[TAB]

My understanding is the 556 also uses thicker brass, so you might have chambering issuses in older 223s  I know they have a chamber that can take both, its basicly the standard now.

[saltydogbk]

My AR's are chambered to shoot both.  When my son and I shoot casually, we use what is cheap.  When he shoots competition, we load our own using Lake City brass, match grade bullets, and V V N135 .  For when the zombies come, we have a pile of 5.56 in various configurations.  My kid likes to shoot so much, I HAVE to use the cheapest available.

[Kilroy]

At a recent technical maintenance class, of 20 AR carbines present, only the two Colts and one RRA had actual 5.56mm chambers, even though every gun in the room was marked 5.56, they actually had .223 chambers.  Brands include RRA, Bushmaster, DPMS, S&W, CMMG and an Armalight.  Most of the users took advantage of the Michiguns brand chamber reamer (found here:  http://www.m-guns.com/tools.php

As the website notes: 

A common problem when firing 5.56 mil-spec ammo in an AR15 with a SAAMI-spec .223 chamber, is that once in a while a spent primer will fall out of a case as it is extracted. Sometimes the primers fall clear and there's no problem, other times they will go under the trigger and get wedged, rendereing the rifle inoperable. I've seen some extreme cases of this where the hammer and trigger were actually hard to get out. I've seen them get wedged between the charging handle and the inside of the receiver, with the bolt out of battery, so that the gun had to have the stock removed so the bolt could be removed to clear the primer. It is not unknown for the primer anvil get stuck on the tubular portion of the carrier key! Popped primers are due in part to the tighter, shorter freebore and shorter, more abrupt throat of the .223 chamber, causing a pressure spike with the hotter, mil- spec ammo.