is 5.56mm ammo the same as 5.56x45
- Thread starter cady1738
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highorder
Member
Yes.
That's quite a purchase.
First AR?
That's quite a purchase.
First AR?
Inebriated
Member
5.56x45 is really 5.56 mm x 45 mm. People just shorten it to "5.56", or "5.56 NATO".
You can also shoot .223 Remington, which is the slightly lower pressure commercial version of 5.56.
You can also shoot .223 Remington, which is the slightly lower pressure commercial version of 5.56.
rcmodel
Member in memoriam
5.56 NATO is 5.56x45 is .223 Remington.
If you have a 5.56 chamber you can shoot them all.
rc
If you have a 5.56 chamber you can shoot them all.
rc
Rubber_Duck
Member
Now you've done it. You've opened the can of worms!
Inebriated
Member
No idea. People have been scooping it up like crazy!
I'd say look at SGAmmo... they get stock in pretty often.
But just go to your local places and buy the $1/round stuff if you really want to shoot. Not a lot of people are buying that in my area.
browningguy
Member
Well since you bought a good rifle why not feed it good ammo. No need to run the cheapest stuff made in it. midwayusa.com had plenty of Black Hills 52 gr. Match ammo on Thursday and Friday.
tahunua001
Member
don't forget 223 Wylde, it can shoot all of those as well,
Ar180shooter
Member
There may be overpressure issues, but I can assure you, hundreds of thousands, if not millions of 5.56 NATO spec rounds have been shot through SAAMI spec chambers without ill effect.
That would assume that anyone cuts a true SAAMI spec .223 chamber. I know of no current production gun that has one. The difference in loading between the 5.56 and .223 loadings combined with the understanding that people are going to shoot the latter because it's available has led pretty much everyone to use a hybrid chamber of some type. Same concept as the Wylde but not the same in most cases. You can get a custom barrel that is a .223 SAAMI spec chamber, but it adds nothing to the equation so why bother.
Ar180shooter
Member
Before the internet (going back a while) it was not a problem to interchange .223 and 5.56.
Yes it also wasn't a problem to load cartridges that proved later to be on the order of proof loads. Ignorance is bliss, until it isn't.
WardenWolf
member
Regarding 5.56 in a .223 chamber, yes, it can cause excessive pressure. However, unless the firearm is severely underbuilt, it typically will not be enough to cause any damage aside from premature throat erosion to the barrel. It's not a "good" thing, but generally it won't really hurt, either. I challenge you to find someone who has had their firearm genuinely damaged by doing this.
I think the issue can be that some 5.56 ammo uses bullets that are so long that they can come into contact with the rifling of a .223 chambered gun which can have a shorter throat.
If the bullet is touching the rifling or close to it before it is fired then the pressure that can build up before it starts making its way down the bore is unacceptable. It needs that little gap to get some velocity before it impacts the rifling. (While too much space can reduce overall accuracy.)
5.56 chambered guns have more throat space.
As a result I really don't think there is any issue at all using 5.56 ammo in .223 guns if you are using ammo that is a similar overall length to .223 ammo.
The ammo is practically the same, and most of the difference in pressure numbers because one is measured in CUP and one in PSI.
However if you are using one of the heavier bullet weights typically only available in 5.56, then you may want to measure the distance in the gun compared to the overall length of the ammo. Insure there is enough space for the bullet to get some velocity before it impacts the rifling.
Those 70+ grain bullets for example can be pretty long and may be unsafe in a SAAMI .223 if they are too close to or in contact with the rifling.
If the bullet is touching the rifling or close to it before it is fired then the pressure that can build up before it starts making its way down the bore is unacceptable. It needs that little gap to get some velocity before it impacts the rifling. (While too much space can reduce overall accuracy.)
5.56 chambered guns have more throat space.
As a result I really don't think there is any issue at all using 5.56 ammo in .223 guns if you are using ammo that is a similar overall length to .223 ammo.
The ammo is practically the same, and most of the difference in pressure numbers because one is measured in CUP and one in PSI.
However if you are using one of the heavier bullet weights typically only available in 5.56, then you may want to measure the distance in the gun compared to the overall length of the ammo. Insure there is enough space for the bullet to get some velocity before it impacts the rifling.
Those 70+ grain bullets for example can be pretty long and may be unsafe in a SAAMI .223 if they are too close to or in contact with the rifling.
Ar180shooter
Member
The other thing to consider is back 30 years ago, you never really saw much of anything heavier than 55gr.
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