I used to reload several years ago. I don't anymore though. My age and health issues. I don't hunt anymore. Really miss it too.
I guess I should try to keep up though.
Posted on 10/29/2016 5:17:13 PM PDT by MtnClimber
Is firing a 5.56 NATO cartridge in your .223 Remington chambered AR15 dangerous? Or do Internet forum-ninjas and ammunition companies selling you commercial ammo instead of surplus overstate the dangers? Believe it or not, a real danger exists, and some gun owners who think they are doing the right thing may not be safe.
The Cartridges
The .223 Remington and 5.56×45 NATO cartridges are very similar, and externally appear the same. But there are some differences that lie beneath the surface.
The 5.56 case has thicker walls to handle higher pressures, meaning the interior volume of the case is smaller than that of a .223. This will alter the loading data used when reloading 5.56 brass to .223 specs.
Some 5.56 loads have a slightly longer overall length than commercial .223 loads.
The Chambers
The significant difference between the .223 Rem and 5.56 NATO lies in the rifles, rather than the cartridges themselves. Both the .223 and 5.56 rounds will chamber in rifles designed for either cartridge, but the critical component, leade, will be different in each rifle.
The leade is the area of the barrel in front of the chamber prior to where the rifling begins. This is where the loaded bullet is located when a cartridge is chambered. The leade is frequently called the “throat.”
On a .223 Remington spec rifle, the leade will be 0.085”. This is the standard described by the Sporting Arms and Ammunition Manufacturers’ Institute, Inc. (SAAMI). The leade in a 5.56 NATO spec rifle is 0.162”, or almost double the leade of the .223 rifle.
(Excerpt) Read more at bearingarms.com ...
I used to reload several years ago. I don't anymore though. My age and health issues. I don't hunt anymore. Really miss it too.
I guess I should try to keep up though.
Does anyone know of any cases of catastrophic damage to the gun, let alone injury to the shooter? It may not be ideal, but I suspect the dangers are overblown. Reloading could be a problem I suppose. Personally I don't own any of either caliber, but I wouldn't hesitate to use 5.56 in a 223.
I have a similar issue with my Garands. .30 M2 vs 30-06 Springfield
I wonder if there is also an issue between .308 and 7.62X51?
If the .30 carbine was good for great grandad in the Pacific it’s good enough for me. Love shooting the M1; been told it’s like a .357 magnum.
Although not identical, the 7.62×51mm NATO and the commercial .308 Winchester cartridges are similar enough that they can be loaded into rifles chambered for the other round, but the Winchester .308 cartridges are typically loaded to higher pressures than 7.62×51mm NATO cartridges.[citation needed] Even though the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) does not consider it unsafe to fire the commercial round in weapons chambered for the NATO round, there is significant discussion about compatible chamber and muzzle pressures between the two cartridges based on powder loads and wall thicknesses on the military vs. commercial rounds. While the debate goes both ways, the ATF recommends checking the stamping on the barrel; if one is unsure, one can consult the maker of the firearm.
I have a Bushmaster AR-15, can I use 5.56?
Reloads in 5.56 brass have to be worked up to avoid overpressure.
That was a consideration when I purchased my M1A.
It will shoot whatever you feed it, with no danger.
He did, however, omit two important differences between the cartridges.
1. Pressures in commercial .223 Remington cartridges and 5.56mm NATO cartridges are determined by two entirely different systems and have different maximum pressure limits. The pressure limits are not interchangeable.
2. In the recent transitioning from the 5.56mm Ball M855A1 to the M855A2 cartridge, the pressure limit for the A2 cartridge was increased to achieve equivalent velocity to the older A1 round. The maximum pressure differential between the .223 Remington and 5.56mm cartridges are now even greater than when the non-interchangeability warnings were first issued. Yes, you might escape catastrophic gun damage and personal injury by ignoring warnings from entities who have far more knowledge about the subject than yourself. Same with firing +P cartridges in guns not designed for the higher pressures. But why would anyone voluntarily take such a foolish risk with no tangible reward other than saving a few pennies?
I have read that there is.
Also a big issue with M1A rifles. They are timed for military ball ammo, you can blow one up with heavy (bullet weight) .308 rounds.
There is almost an identical issue with .308 vs 7.62x51. Only in this case it is the civilian .308 which are typically loaded for higher pressures. Despite this the military brass is actually heavier. I use mostly surplus once fired 7.62x51 military brass to make up cartridges, but I also save the brass from civilian .308 that I have purchased over the years. In the rifles we use and with the recipes I carefully follow... it is not a safety issue, but the brass needs to be kept separated or you will definitely end up with cartridges that do not behave the same when they are loaded with the same powder charge and projectile. And I have confirmed this with a chronograph.
5.56x45 NATO vs .223 Rem How To Determine Your Rifle Chamber
https://www.youtube.com/watch?v=xepLT-x58JQ
I have never had a problem firing 5.56 in a .223, only in reloading due to lower case volume in the 5.56. The article warns of lede dimension (I am guessing these are industry standards for MINIMUM dimension). You could chamber a 5.56 and eject it. If you don’t see any barks on the bullet from where it contacted the rifling in the barrel then you should be good to shoot it.
Not quite right, if you use a heavy bullet the action can unlock before the bullet exits the barrel causing a Kaboom. At least one freeper has blown up his M1A, I remember reading his story years ago. I later learned about how that happens.
I love the M1A but I have limited my shooting to military ball or light weight .308 rounds.
And primers blown out the case which wind up rattling around in your receiver.
As well as higher pressures the 5.56 cartridge has a slightly longer case neck. The bullet is supposed to make a short `jump’ before engaging the rifling in the barrel. A barrel with a 5.56 leade allows this to happen.
A .223 barrel has a slightly shorter leade, so the bullet from a 5.56 cartridge leaves the cartridge then immediately engages the rifling which confuses it, so it becomes angry with you and puts your eye out.
Great GrandDad?
I love my M1-Carbine too. Maybe more than my M1 Garands.
“barks” should be “marks”.
Great, thanks!
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