223 Rem VS 5.56mm-

[Moebrown20]

223 Rem VS 5.56mm-

There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.

The cartridge casings for both calibers have basically the same length and exterior dimensions.

The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.

The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.

The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.

You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.

Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.

The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (http://en.wikipedia.org/wiki/Sporting_Arms_and_Ammunition_Manufacturers%27_Inst itute)(Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.

Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges. Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy.

However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.
************************************************** ************************************************** *****************************
With the price of ammo being what it is today, it's best to be safe BEFORE going to the range


Link: http://en.wikipedia.org/wiki/.223_Remington

[abpt1]

223 Rem VS 5.56mm-

There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.

The cartridge casings for both calibers have basically the same length and exterior dimensions.

The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.

The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.

The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.

You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.

Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.

The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (http://en.wikipedia.org/wiki/Sporting_Arms_and_Ammunition_Manufacturers%27_Inst itute)(Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.

Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges. Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy.

However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.
************************************************** ************************************************** *****************************
With the price of ammo being what it is today, it's best to be safe BEFORE going to the range


Link: http://en.wikipedia.org/wiki/.223_Remington



When you start reloading this size issue is null since you seat your bullets to the size of your chamber ..


http://www.midwayusa.com/viewProduct/?productNumber=570611http://www.qtl.co.il/img/copy.pnghttp://www.google.com/favicon.ico (http://www.google.com/search?q=or%20something%20mid%20range%20that%20wor ks%20in%20a%20few%20rifles.)http://www.qtl.co.il/img/trans.png

[Gunreference1]

Another source of information on the .223 vs. 5.56 issue.

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

Steve

[Paladin]

223 Rem VS 5.56mm-...There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.

Moe, all good stuff. I decided on a .223 Wylde chamber years ago. Has worked out well; .223 Rem, 5.56 NATO, reloads...

[Krupski]

My Colt AR-15 rifles are stamped "Cal 5.56mm" while the Bushmasters are "Cal .223".

I've put .223 and 5.56 through both rifles (that is, all 4 combinations) and there seems to be no difference in performance or accuracy between .223 and 5.56mm.

HOWEVER, my Bushmaster rifles are more accurate than the Colts, regardless of ammo. With a sandbag rest I can easily make "1 ragged hole" at 50 yards with my Bushys while the Colts will be all over a 3 inch circle.

I don't know why... except maybe it's the barrel twist? (1:9 in the Bushy and 1:7 in the Colt)?

Also, I assume (oh shit here I go assuming again!)... I assume that the XM193 ammo that's always available is 5.56 military ammo that just didn't meet some spec?

I've felt no difference between firing .223 and 5.56 ammo... I've even loaded a mag with alternating calibers and they feel the same.

If 5.56 is "loaded hotter" shouldn't I feel a difference in recoil?

[El Jefe]

Interesting, my Bushmaster operators manual states that it's safe to shoot both .223 and 5.56, but I've only shot .223 through it because that's what I can easily find here locally. I've always been under the impression that most/all AR15's could safely shoot both.

:think:

[RJ Shooter]

Most ARs are chambered for the 5.56 round. Some manufacturers put .223 on their receivers because 'non-gun' people look at the 5.56 as a 'military' round, thus making the AR a 'military assault weapon!' They started stamping them this way more in the mid 90s when gun bans were the rage.

Some bolt guns and BR pistols and rifles are literally chambered for .223 and not 5.56, but with the amount of surplus ammo that 'was' around for the last decade, just about everyone chambers for 5.56mm.

[NewbieAKguy]

Good info. How about .308 Win. vs. 7.62x51?

[mriddick]

Good info. How about .308 Win. vs. 7.62x51?

It's the opposite in some ways, most 308 win loads have more pressure then the nato loading.

About the only time 223 or 556 is worrisome to me is when bullet leade comes into play (and that's not lead as the mineral but leade as in how far the bullet has to go to engage the riflings). Some 556 loads can engage the riflings of a 223 chambered load to the point of pulling bullets out of the casing.

[abpt1]

It's the opposite in some ways, most 308 win loads have more pressure then the nato loading.

About the only time 223 or 556 is worrisome to me is when bullet lead comes into play (and that's not lead as the mineral but lead as in how far the bullet has to go to engage the riflings). Some 556 loads can engage the riflings of a 223 chambered load to the point of pulling bullets out of the casing.

too much lead on bullets can cause a discharge ....If you try to jam the bolt closed on a long seated round meaning.. if you load it to where it actually does touch the rifling..then force it closed IT WILL DISCHARGE !

http://www.qtl.co.il/img/copy.pnghttp://www.google.com/favicon.ico (http://www.google.com/search?q=99%25)http://www.qtl.co.il/img/trans.png

[Gunreference1]

http://thegunzone.com/30cal.html

Steve

[Paladin]

http://thegunzone.com/30cal.html

Steve

Thanks...

[mriddick]

too much lead on bullets can cause a discharge ....If you try to jam the bolt closed on a long seated round meaning.. if you load it to where it actually does touch the rifling..then force it closed IT WILL DISCHARGE !


I have never heard of or seen this, I'm not even sure about the mechanics of how it could be done. Compressing the charge by pushing the bullet back into the case will cause an increase in pressure, having the bullet touching the riflings can also cause an increase of pressure (either of which are dangerous) but I doubt the round will discharge on this action alone. Am I reading you wrong?

[abpt1]

I have never heard of or seen this, I'm not even sure about the mechanics of how it could be done. Compressing the charge by pushing the bullet back into the case will cause an increase in pressure, having the bullet touching the riflings can also cause an increase of pressure (either of which are dangerous) but I doubt the round will discharge on this action alone. Am I reading you wrong?
I have heard this happening on bolt action rifles. The inertia of slamming it closed can make the firing pin protrude slightly and could set off a primer also apparently when forcing the bolt closed any thing from dirt or the weight of the unset hammer or bolt face erosion. I know someone who has actually happen or read it some where Let me research it a bit so I can site some thing ...credible

[HDR]

I'd be more concerned about the different lengths than slamming the bolt that hard. Probably because if the bolt doesn't close easily I'm going to stop to see why.