5.56 or .223?

So I am having a heck of a time finding either round for my AR-15 but I do occasionally see a .223 at Fleet Farm, Cabelas and Gander. Of course they sell out of it almost immediately.

I sighted the gun in using a holographic site at 100 yds using 5.56 but am out of that ammo.
Question I have is .223 so ballistically similar to 5.56 that I can site in using .223 and the 5.56 will still be close or does the extra fps from the 5.56 make a significant difference? They are wanting 50 cents or more a round right now for the cheap .223 brands, which still is overpriced but what choice does a guy have to be prepared when S.H.T.F.?

I have been hoping things will calm down and I could eventually find good 5.56 for under 30cents a round like it used to be.

.223 Ballistics wise…. They really isn’t much difference in drop than the 5.56. Some .223 shoot faster than the 5.56 on the hornady ballistic chart. All depends on what you buy.

If you can get lucky and find a pair of .223 and 5.56 that shoot the same like hole on hole match up good luck!

Every cartridge shoots a bit different so if you are gonna shoot .223 then shoot that and move the site. They might only be an inch apart left to right or up and down. I would always recommend sighting in for what you are using.

A 5.56 is a .223 and vice versa. There is no dimensional or technical difference between the two. Therefore, you can’t really draw performance generalizations based only on the printing on the ammo box.

What does differ is how they are loaded and with what bullet. Both bullet and powder are going to alter your consistency and POI.

It isn’t technically correct to say that all 5.56 ammo is higher velocity than .223, BTW. This is an urban legend based on the assumption that everything labeled 5.56 is made to US military specs. Which it is not.

There is no reason why commercial ammo can’t produce velocities like mil-spec ammo. Hornaday’s Superformance and many handloads do just that–produce velocities at or above the mil-spec minimums for 5.56.

The bottom line is that no two brands are going to produce exactly the same accuracy. Also, keep in mind that velocity isn’t everything. Very, very rarely do my fastest handloads produce the best accuracy. Bullet selection plays a VASTLY greater role in overall accuracy.

One last point and please don’t take this as a dis on your shooting abilities. I’m only bringing this up as a factor to consider. Depending on how well you shoot with it, using a holographic site at 100+ yards, may put you within the margin of error of one or more brands of ammo. By that I mean that you won’t be able to discern a performance/accuracy difference between brands because, essentially, the ammo is capable of accuracy in excess of the consistency you can produce given the limitations of your optics.

Again, I’m not commenting specifically on your marksmanship skills. I’m just saying that the limits of the sighting apparatus used are part of the whole equation.

Grouse

Nice write up FG

Just in case someone else is reading this ONLY 5.56 IF YOUR 223 SPECIFICALLY SAYS 5.56 Normally 5.56 can run higher pressures then 223 which many 5.56 shells can and do..

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Just in case someone else is reading this ONLY 5.56 IF YOUR 223 SPECIFICALLY SAYS 5.56 Normally 5.56 can run higher pressures then 223 which many 5.56 shells can and do..

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I might be misunderstanding you, but I think you meant it the other way around.

Only .223 ammo if your rifle says .223 Remington. A rifle chambered specifically for the 5.56 can shoot either.

The technical spec for a .223 Remington chambering specifices a shorter leade than the 5.56 specification, which calls for a longer leade and therefore will accomodate (I believe) up to 10,000 PSI of increased chamber pressure.

Now where it gets tricky is that weather or not this matters depends on the chamber pressure of the individual load. It could be safe to fire a 5.56 round in a .223 IF (IF!) you KNOW that load specs and therefore know the chamber pressure is within the specifications for your rifle.

Grouse

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Just in case someone else is reading this ONLY 5.56 IF YOUR 223 SPECIFICALLY SAYS 5.56 Normally 5.56 can run higher pressures then 223 which many 5.56 shells can and do..

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I might be misunderstanding you, but I think you meant it the other way around.

Only .223 ammo if your rifle says .223 Remington. A rifle chambered specifically for the 5.56 can shoot either.

The technical spec for a .223 Remington chambering specifices a shorter leade than the 5.56 specification, which calls for a longer leade and therefore will accomodate (I believe) up to 10,000 PSI of increased chamber pressure.

Now where it gets tricky is that weather or not this matters depends on the chamber pressure of the individual load. It could be safe to fire a 5.56 round in a .223 IF (IF!) you KNOW that load specs and therefore know the chamber pressure is within the specifications for your rifle.

Grouse

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My 223`s state both calibers if it is rated for 5.56, so both are stamped on the barrel.