5.56 A Superior Round?

[Abraham]

Is there any benefit to shooting 5.56 ammo vs. .223?

Or, is there no real benefit and maybe some drawbacks like cost, availability, etc.?

Thanks!

[Beiruty]

Is there any benefit to shooting 5.56 ammo vs. .223?

Or, is there no real benefit and maybe some drawbacks like cost, availability, etc.?

Thanks!

Upon an impact, your target would not "feel" a difference.

[nightmare69]

You can feel the difference in recoil going from 223 to 556.

[MoJo]

If your rifle has a 5.56 chamber then there's little difference between the two. If it has a .223 chamber you should not shoot 5.56 due to the higher pressure of the 5.56 ammo. As Beiruty said there's little difference in terminal performance.

[gthaustex]

Decently interesting reading if you are so inclined....

http://www.luckygunner.com/labs/5-56-vs-223/

[HankB]

From a 24" barrel, Hornady claims their .223 75 grain BTHP TAP FPD ammo produces 2790 ft/sec muzzle velocity.
Also from a 24" barrel, their .223 75 grain BTHP Superformance Match ammo is claimed to produce 2930 ft/sec.
From a 20" barrel, the Hornady 5.56mm BTHP T2 TAP produces 2858/2861 from two different barrels.

Hornady claims their 55 grain GMX Superformance .223 ammo will produce 3275 ft/sec from a 24" barrel.
Their 55 grain GMX Tap Barrier 5.56mm ammo produces 3267/3319 ft/sec from a couple of 20" barrels.

Taking into account barrel length, I'd say Hornady loads their 5.56 ammo a bit hotter than their .223 ammo, even their Superformance stuff. So from a purely ballistic standpoint, Hornady's 5.56mm is superior. Cost and availability? That's an open question.

That's one manufacturer. Others? Your guess is as good as mine.

[Dadtodabone]

Depending on barrel length and twist rate there are, IMO, 3 superior rounds for the 5.56 chambered rifle that out perform the .223. One is the aforementioned Hornady TAP.
Another is the Black Hills 5.56 OTM 77gr aka Mk262 Mod1. To realize the long range potential of the OTM your rifle barrel would need to be a 1 in 7 twist rate with a length of 20" or greater. In 18" SPRs and 14.5" M4s with 1:7 barrels the OTM will still out perform M855 or other commercial loads by a wide margin.
http://www.shootingtimes.com/2012/03/21 ... -1-review/
Finally the USMC developed Mk318 Mod0 SOST 5.56, available as the Federal 5.56 62gr BTHP is another great performer in shorter barrel rifles and is designed to be barrier blind. Again, due to the bullet weight, a fast twist rate is needed to stabilize said bullet, 1:9 - 1:7 barrels will allow this round to meet it's design potential.
http://www.thefirearmblog.com/blog/2010 ... mmunition/
While I am unable to speak to the OTMs lethality, other than on a few hogs at ranges under 300 yds, I have been very impressed with the accuracy of the round through several 20" rifles when using a precision optic. Center of mass at 500 yards on full size silhouettes is a common occurrence and a once in a while thing at 600 even for a half blind old crip like me.

[carrydave]

keep in mind that basically every rifle has a wylde (hybrid) chamber nowadays.

[Abraham]

Thanks everyone!

I'm learning.

[TheDude]

keep in mind that basically every rifle has a wylde (hybrid) chamber nowadays.

Not sure why you would say that. Most ARs are 5.56 chambered which will fire both rounds. Some rifles are chambered for .223 wylde but they should say .223 wylde on the barrel. If it just says .223 then it is dangerous to shoot 5.56 in the rifle.



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[ComeAndTakeIt]

keep in mind that basically every rifle has a wylde (hybrid) chamber nowadays.

Not sure why you would say that. Most ARs are 5.56 chambered which will fire both rounds. Some rifles are chambered for .223 wylde but they should say .223 wylde on the barrel. If it just says .223 then it is dangerous to shoot 5.56 in the rifle.

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[JSThane]

keep in mind that basically every rifle has a wylde (hybrid) chamber nowadays.

Not sure why you would say that. Most ARs are 5.56 chambered which will fire both rounds. Some rifles are chambered for .223 wylde but they should say .223 wylde on the barrel. If it just says .223 then it is dangerous to shoot 5.56 in the rifle.

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Getting into the minutiae here, but I'm curious on a couple things with reference to this, specifically how it is dangerous to fire 5.56 in a .223 chamber. I'm aware I'm ranging into the pedantic here, but looking at my loading manuals, the external dimensions of both cartridges are, as we all know, identical. Therefore, it cannot be a difference in the cartridge itself (not yet getting into case wall thickness or pressure levels, more later).

I thought, "Well, maybe it's because the 5.56 has a longer throat and Overall Length, so it's an overpressure from hitting the rifling lands," except COL for the 5.56 is listed as .01" -shorter- than the .223, so that can't be it. (Info from Hornady manual, 5th edition)

So, overall velocities and pressures must be the culprit. The Hornady manual doesn't list data for identical bullets across the two cartridges, stopping at 60 grains for .223, and starting at 68 for 5.56. Unfortunately, it also fails to list pressures, so can't do a comparison there. Lee and Lyman both list pressure, but neither makes any distinction between the two. Probably the most complete manual I own, the Speer manual, mentions the 5.56 merely in passing as another name for the .223. No manual lists any pressure difference between the two, nor do they advise against firing either one in the other. In fact, Hornady lists loads for several of its bullets that are right up there, velocity-wise, with the above-mentioned 5.56 loads. The 5.56 is -slightly- hotter, but absent any actual pressure data to indicate otherwise, I don't see any real practical difference.

Given that barrels are proof-tested with deliberately grossly over-loaded rounds, a slight increase between 5.56 and .223 seems neglible. I could see how a steady diet of the hotter ammo, over a period of several years, could prematurely wear certain parts in the gun, but I fail to see how using 5.56 in a .223 is dangerous.

Thus, could you provide examples and references showing me I'm wrong? Not meaning any offense, but this brings back memories of people telling me not to fire .308 in my 7.62 Mauser, because it was dangerous, yet AFAIK, there was never a single example of a 7.62 Mauser blowing up due to the slightly hotter ammunition, only a "this might maybe could possibly stand a slight chance of happening, so it's dangerous to even think of it."

[The Annoyed Man]

You can feel the difference in recoil going from 223 to 556.

Speaking strictly seat of the pants, I'd agree. The NATO ammo I've shot seems to be loaded hotter than the commercial .223 ammo, given similar bullet weights. While neither has significant recoil (a .308 will thump you, while a .223 has next to no recoil at all), the NATO ammo does seem to produce a slightly stronger recoil impulse.

[The Annoyed Man]

Depending on barrel length and twist rate there are, IMO, 3 superior rounds for the 5.56 chambered rifle that out perform the .223. One is the aforementioned Hornady TAP.
Another is the Black Hills 5.56 OTM 77gr aka Mk262 Mod1. To realize the long range potential of the OTM your rifle barrel would need to be a 1 in 7 twist rate with a length of 20" or greater. In 18" SPRs and 14.5" M4s with 1:7 barrels the OTM will still out perform M855 or other commercial loads by a wide margin.
http://www.shootingtimes.com/2012/03/21 ... -1-review/
Finally the USMC developed Mk318 Mod0 SOST 5.56, available as the Federal 5.56 62gr BTHP is another great performer in shorter barrel rifles and is designed to be barrier blind. Again, due to the bullet weight, a fast twist rate is needed to stabilize said bullet, 1:9 - 1:7 barrels will allow this round to meet it's design potential.
http://www.thefirearmblog.com/blog/2010 ... mmunition/
While I am unable to speak to the OTMs lethality, other than on a few hogs at ranges under 300 yds, I have been very impressed with the accuracy of the round through several 20" rifles when using a precision optic. Center of mass at 500 yards on full size silhouettes is a common occurrence and a once in a while thing at 600 even for a half blind old crip like me.

My son has a 24" stainless bull barreled Rock River Arms varmint rifle that puts 4 rounds of that Black Hills OTM into .25" at 100 yards and will do that all day long. The dang rifle weighs about 15-16 lb though, so it's not something you just tote around.

[Dadtodabone]

Depending on barrel length and twist rate there are, IMO, 3 superior rounds for the 5.56 chambered rifle that out perform the .223. One is the aforementioned Hornady TAP.
Another is the Black Hills 5.56 OTM 77gr aka Mk262 Mod1. To realize the long range potential of the OTM your rifle barrel would need to be a 1 in 7 twist rate with a length of 20" or greater. In 18" SPRs and 14.5" M4s with 1:7 barrels the OTM will still out perform M855 or other commercial loads by a wide margin.
http://www.shootingtimes.com/2012/03/21 ... -1-review/
Finally the USMC developed Mk318 Mod0 SOST 5.56, available as the Federal 5.56 62gr BTHP is another great performer in shorter barrel rifles and is designed to be barrier blind. Again, due to the bullet weight, a fast twist rate is needed to stabilize said bullet, 1:9 - 1:7 barrels will allow this round to meet it's design potential.
http://www.thefirearmblog.com/blog/2010 ... mmunition/
While I am unable to speak to the OTMs lethality, other than on a few hogs at ranges under 300 yds, I have been very impressed with the accuracy of the round through several 20" rifles when using a precision optic. Center of mass at 500 yards on full size silhouettes is a common occurrence and a once in a while thing at 600 even for a half blind old crip like me.

My son has a 24" stainless bull barreled Rock River Arms varmint rifle that puts 4 rounds of that Black Hills OTM into .25" at 100 yards and will do that all day long. The dang rifle weighs about 15-16 lb though, so it's not something you just tote around.

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I really like the OTM. My bug out bag prepped magazines and bulk ammo are exclusively OTM. The line in the article that goes something like "we knew it was good when the assaulters were stealing it from the snipers" was what led me to investigate the load.
I've taken 3 hogs with this round, 2 were DRT and one made about 10 yards. First one I was shooting a LaRue LT011 20" upper on a Colt lower w/Geissele DM Rifle Trigger, S & B 1-8 x 24 Short Dot(magnificent). Not an optimal configuration, but, the opportunity presented itself when a sounder wandered into view when visiting a friend's new peanut farm he hoped to convert to a large shooting facility.
No exit wounds on any of the hogs, largest recovered fragment weighed 28 grains.