5.56 and .223 mixed?

[cams]

I understand the basic differences between the two rounds, and have only ever bought or acquired 5.56, it’s what I prefer to keep on hand and my rifles are only 5.56/multi, none are solely .223.

I also understand the basic concept that you can shoot down (.223 in 5.56) but should never shoot up (5.56 in a .223) due to gas pressure issues I think it is.

So my probably very basic question, has anybody ever mixed rounds in the same mag and if so are there any issues around that with misfeeds or jamming having them both in the same mag.

Or, are the casings the exact same size externally and 5.56 is just a thicker casing internally? Clear as mud? lol

Just generally boredom wondering if in a bad situation you need to restock some mags on the move and there being so much .223 out there it’s something I hadn’t thought of before.

 

[Arto]

there are some famous articles:

.223 Remington vs. 5.56x45mm — Facts vs. Fiction « Daily Bulletin

Probably the most popular centerfire rifle round in the Western Hemisphere is the .223 Remington and its metric match, the 5.56x45mm. Though many folks use .223 Rem and 5.56x45 interchangeably, there are some meaningful differences in specifications for the original .223 Rem and the 5.56x45mm...

bulletin.accurateshooter.com

.223 Remington Vs. 5.56: What's in a Name?

The common misconception is that the two are the same—that 5.56x45 mm and .223 Rem. are the same dance partner, but with a different dress. This can lead to a dangerous situation

www.americanrifleman.org

.

 

[xtry51]

I've never seen a diff and I'm notorious for keeping a training can full of leftovers from different batches and vendors.

 

[cams]

years ago, I heard that you should never "mix" different brands/styles of rounds in a magazine (probably an old Shrewsbury Gun Room myth), but it really never made any sense to me, what's actually the difference if you really think about it? Nothing. If your gun is designed to handle that caliber, it simply shouldn't matter. The only perceived differences may be recoil or accuracy, other than that, it won't affect reliability or wear on you gun. Maybe I'm wrong, who knows

To clarify, I know I can shoot .223 all day long in a 5.56, but directly having.223 and 5.56 in the same mag, is what raised my question. It’s my understanding that 5.56 has a thicker casing to protect it from burn off and being fired on burst or auto for extended periods, whereas .223 would allegedly cook off from the heat because it has a thinner casing. So would that thinner casing following a thicker casing cause a jam in the mag or misfeeds when chambering?

 

[cams]

there are some famous articles:

.223 Remington vs. 5.56x45mm — Facts vs. Fiction « Daily Bulletin

Probably the most popular centerfire rifle round in the Western Hemisphere is the .223 Remington and its metric match, the 5.56x45mm. Though many folks use .223 Rem and 5.56x45 interchangeably, there are some meaningful differences in specifications for the original .223 Rem and the 5.56x45mm...

bulletin.accurateshooter.com

.223 Remington Vs. 5.56: What's in a Name?

The common misconception is that the two are the same—that 5.56x45 mm and .223 Rem. are the same dance partner, but with a different dress. This can lead to a dangerous situation

www.americanrifleman.org

.

Thanks, I’ll give those a good read tonight.

 

[mcshooter]

I think it's time for a range trip to try this out

 

[cams]

I think it's time for a range trip to try this out

Same. I thought of this earlier because my eyes are getting pretty bad, need readers just to view this on my phone. If I had a 5.56 round and a .223 round in my hand, I can’t tell the difference by look or feel, and I can no longer read the small print on casings anymore. Just some boredom and “hey I never thought of this before” and “f*** I’m getting old”.

 

[Tinkermatic]

Have mixed both in a mag before with no issues. I try not to, but, sometimes it happens.

 

[cams]

Have mixed both in a mag before with no issues. I try not to, but, sometimes it happens.

Good to know, thank you. Guess I’ll also have to get some range tests done as well.

 

[greencobra]

almost every modern ar style rifle is marked 5.56.

i'm not gonna look it up but for some reason i have in my head, the shoulder angles are not the same as well. i doubt anyone would know the difference if the 2 different ammos were mixed in a mag. i've always believed it was like, say, 2 revolvers, one +p and the other isn't. you can shoot +p in the one marked for regular ammo, it won't disintegrate but it's not healthy for it to have a steady diet.

 

[Twigg]

Go with a wylde chamber upper and cease worry.

 

[Uzi2]

Look up "School Of The American Rifle" on youtube.

The difference is in the throat cut/length of the chamber, 5.56 is longer and looser than .223

He uses a "chamber function gauge" ( not a headspace gauge ) to measure the throat cuts of barrel chambers.

Headspace measures from the shoulder back to the bolt face, whereas a chamber function gauge measures the throat depth and diameter. If a 5.56 chamber function gauge sticks in a marked 5.56 barrel, the throat is either burred, not cut correctly for 5.56 or the barrel is mismarked and possibly a .223 chamber cut.

.223, .223 Wylde and 5.56 are all cut differently.

All of my chambers are Wylde or 5.56 and I've not had any issues using differently loaded mags.

 

[Uzi2]

almost every modern ar style rifle is marked 5.56.

i'm not gonna look it up but for some reason i have in my head, the shoulder angles are not the same as well. i doubt anyone would know the difference if the 2 different ammos were mixed in a mag. i've always believed it was like, say, 2 revolvers, one +p and the other isn't. you can shoot +p in the one marked for regular ammo, it won't disintegrate but it's not healthy for it to have a steady diet.

But the +P thing in a revolver is not a chamber issue, it's a metallurgy issue or gun design issue in semiautos where the gun itself is not designed for the pressures/hard recoiling of the slide.

I've fired +P in guns not marked for it, but not a steady diet. The Ruger P85/90 series 9mm guns will take it.....I've shot the Hirtenberger 9mm subgun ammo ( now almost unobtainium) in them all day with no ill effects...hits point of aim at 100yds consistently.

 

[greencobra]

But the +P thing in a revolver is not a chamber issue, it's a metallurgy issue or gun design issue in semiautos where the gun itself is not designed for the pressures/hard recoiling of the slide.

yes, true!

 

[Quantavious G]

follow on question. The 5.56 generates higher pressure than the 223. Does that make the 5.56 more powerful in terms of stopping power? Or is a 5.56 round from a 5.56 chamber have the same power as a 223 fired from a 223 chamber?

 

[Uzi2]

follow on question. The 5.56 generates higher pressure than the 223. Does that make the 5.56 more powerful in terms of stopping power? Or is a 5.56 round from a 5.56 chamber have the same power as a 223 fired from a 223 chamber?

Stopping power is a multi function issue, velocity, bullet weight/mass, bullet design, caliber, target make up, etc.

Get enough drugs into someone and they might take a dozen non critical area hits before going down.

I think the answer to your question would be.....the difference would be negligible given the same bullet from either.

 

[FPrice]

Timely thread. I am in the process of getting active again and am looking at what to feed my AR. But, not so much mixing .223 with 5.56 as working on feeding it the same weight bullet. I'll be reading these articles this weekend.

 

[cams]

All of my chambers are Wylde or 5.56 and I've not had any issues using differently loaded mags.

Differently loaded as in, one mag of 5.56 and one mag of .223? Or actual use with both rounds in the same mag? That is my question. Not about pressure or head space, just the casings and would they jam up being of diff specs and in the same mag together.

 

[Uzi2]

Differently loaded as in, one mag of 5.56 and one mag of .223? Or actual use with both rounds in the same mag? That is my question. Not about pressure or head space, just the casings and would they jam up being of diff specs and in the same mag together.

Different ammo in the same mags. If I end up with loose ammo, I just stuff them in a mag for range practice.

My chambers will take .223 or 5.56 so I have no worries about mixed ammo in the same mag.

 

[cams]

Different ammo in the same mags. If I end up with loose ammo, I just stuff them in a mag for range practice.

My chambers will take .223 or 5.56 so I have no worries about mixed ammo in the same mag.

Gotcha. Ya mine as well. I may not have explained the OP well, I’m a few drinks in, it was the mags jamming up (or not) that got me interested.

 

[chris_1001]

I understand the basic differences between the two rounds, and have only ever bought or acquired 5.56, it’s what I prefer to keep on hand and my rifles are only 5.56/multi, none are solely .223.

I also understand the basic concept that you can shoot down (.223 in 5.56) but should never shoot up (5.56 in a .223) due to gas pressure issues I think it is.

So my probably very basic question, has anybody ever mixed rounds in the same mag and if so are there any issues around that with misfeeds or jamming having them both in the same mag.

Or, are the casings the exact same size externally and 5.56 is just a thicker casing internally? Clear as mud? lol

Just generally boredom wondering if in a bad situation you need to restock some mags on the move and there being so much .223 out there it’s something I hadn’t thought of before.

I doubt you’d notice a shot for shot difference if you staggered .223 and 5.56 in the same mag. If so might be a tiny bit of bullet drop or recoil impulse. But It would be soooo ever so slight.

I shoot both (5.56 barrel) I don’t re zero or notice any recoil difference.

 

[cams]

I doubt you’d notice a shot for shot difference if you staggered .223 and 5.56 in the same mag. If so might be a tiny bit of bullet drop or recoil impulse. But It would be soooo ever so slight.

I shoot both (5.56 barrel) I don’t re zero or notice any recoil difference.

I do appreciate the reply, but my question had nothing to do with recoil or drop. It was only about the specs being different and possibly jamming up while feeding from the mag or getting all f***ed up inside the mag.

 

[chris_1001]

I do appreciate the reply, but my question had nothing to do with recoil or drop. It was only about the specs being different and possibly jamming up while feeding from the mag or getting all f***ed up inside the mag.

Gotcha. I load both in the same mags. No hiccups switching between .223/5.56. My AR’s eat both fine, no issues.

It’s all about the barrel. If yours is marked 5.56 you are 100% fine swapping them.

I swap between wolf gold .223 and lake city xm193/855.

Never had an issue.

 

[citoriguy]

I’ve done this before and had no mag issues or jamming of any kind. I was using Colt 10 and 20 rounders in an Aero Precision AR (matching upper and lower) and nothing unusual happened whatsoever.

 

[drgrant]

Years ago when I would get what I would call "garbage lots" of ammo sometimes there was both mixed in, you could tell because 556 was louder than the 223 shots etc... and obviously if you
chronoed them.... pretty significant difference there... but function wise? never really a problem. Obviously in a fighting setup or "serious business" you would want to know what loads you were
running... but if you're just doing generalized blasting/drills/etc.... nbd, imo.

 

[chris_1001]

I’ve done this before and had no mag issues or jamming of any kind. I was using Colt 10 and 20 rounders in an Aero Precision AR (matching upper and lower) and nothing unusual happened whatsoever.

Mine are a mix of upper/lowers. I do try and stick with Colt mags and in a free state I have used p-mags.

Again 100% interchangeable. Only issues I’ve ever had was with lacquer coated steel cased ammo. But a separate topic.

 

[cams]

I doubt the case thickness has any relevance to cook off, it's probably in the thousands of inches, if any, the main difference is the in the throat of the rounds, the 5.56 has a longer throat to allow for excess fouling, other than that there's no real difference.

That’s what we were always told, about the thinness and cook offs. I’m no ammo specialist and ‘specs’ and things like that don’t interest me in the least so I never looked at it closely. Just a grunt with drinking questions.

 

[chris_1001]

Never looked at the thickness spec, but the OD of the case has to fit the chamber. So if it’s thicker, it’s a smaller ID.

 

[Mtn_Guy]

Both .223 and 5.56 feed/function fine when loaded as a mixed lot into a standard-capacity USGI pre-ban with a Magpul replaced follower. I’ve done this deliberately to see if I can “feel” the difference in the perceived recoil, as well as check for reliability Issues with the gun. On slow and deliberate single string of fire, I swear I can tell the difference. Had a buddy load several mixed mags and we’d take turns calling the caliber and then checking the brass. Could have been real good guessing, or maybe there was a perceived difference. On multi-shot groups, or engaging multiple targets neither of us could tell a difference. We weren’t checking casings either. I’ll also note, we were shooting 62 Gr 5.56 and 55 Gr .223.

Anyways, I generally shoot 55 Gr .223 for target and keep the 62 Gr penetrators for the zombie hoards.

I’ve noticed the real difference is in spread at 100 yds, where the lighter round will open up on pattern spacing. Realizing this, I focus more on aim small, miss small.

 

[Tinkermatic]

As others have said, there are indeed slight differences in the chambers intended for the two rounds, namely the free bore length. If you test the cartridges themselves using the same methods, SAAMI (which the military does not) they’ll produce almost the same pressure of 55,000 psi. However, Because the free bore length of a .223 chamber is half that of a 5.56 (.0025 vs .0050 according to this guy) depending on the the actual bullets, you can end up with some varied chamber pressures that may not be healthy. This is from a reloading channel. He does a much better job than me and I’m just regurgitating his info anyway.

View: https://youtu.be/VCS4fXFmCyA