Sighting in an AR with .223 or 5.56, difference?

[Goober135]

Went to Kingsbury today. Got some interesting results with my Stag AR.

Here's my target @ 100yds (It's supposed to be rotated right but im posting from my phone and can't figure out how)

I sighted the rifle using .223. I shot this target with both .223 and 5.56. It seemed like the 5.56 pulled right whereas the .223 was on target. Am I just a bad shot or is there more to this? This is only the second time I've shot my AR and the first time @ 100yds, so if I'm missing some common knowledge fill me in!

 

[mvician]

The 5.56 is a different beast than the .223 and will not shoot to the same point of impact.

 

[Goober135]

So the fact that they hit right isn't a surprise?

 

[sloughfoot]

You are a bad shot. There is no difference between .223 and 5.56. At least the 55 grain offerings.

 

[mvician]

So the fact that they hit right isn't a surprise?

No


That's why you zero the rifle for an ammo type, whether it is .223 or 5.56 or different bullet weights.

If you're just plinking it doesn't matter if you mix ammo types. But if you are doing some serious shooting you want to stick to one type of ammo.

 

[Kart29]

different brands of ammo, different bullet weights, bullet construction, different powder, even different primers can all have an effect on a bullet's point of impact.

Generally, you sight a rifle in for one particular kind of ammunition and expect it to hit conistantly in the same spot. Whenever you change ammuntion, even a seemingly small change, the bullets will normally hit in a slightly different location. Could be high, low, left right. You just never know until you start shooting targets.

 

[mvician]

You are a bad shot. There is no difference between .223 and 5.56. At least the 55 grain offerings.

 

[sloughfoot]

Yes, there is no difference between 55 grain .223 and 5.56 loads.

The M855 62 grain loads are a different matter, because of throat length.

Read the literature, it says it very clearly if you take the time to really read it.

Dare to upset the internet apple cart.

 

[Charlie2]

If there is No difference .. why is one .223 and the other 5.56.. ??? The bullet might weigh the same grains but the loads are different ...

 

[Goober135]

 

[sloughfoot]

No sir, there is absolutely no difference between the two 55 grain loads. They are both loaded to the same velocity. The cartridges are both identical in size and in every dimension.

There is only an difference when considering the 62 grain NATO load. And it only has to do with throat length. In other words, the chamber is slightly different, not the cartridge dimensions.

Read the data very carefully, it is there. believe it or not, everything that seems established on the internet may not be true.

 

[mvician]

http://ammo.ar15.com/project/AmmoOracle_061808.pdf

 

[jd4320t]

I may be lost but I can tell a difference between AE 223 and AE 556. Both are 55gr.

 

[Charlie2]

Yep.. I knew they were different..!! The 5.56 is usually loaded to higher pressures..!! So if your barrel is chambered for .223 it would be unsafe to shoot 5.56..

 

[mvician]

.223 The .223 Remington has 1.87 ml (28.8 grains H2O) cartridge case capacity.

5.56The 5.56×45mm NATO has 1.85 ml (28.5 grains H2O) cartridge case capacity.

 

[sloughfoot]

Sigh, there is no difference between the pressures of a 5.56 or 223 55 grain load. They are identical. Instead of just reading the internet, chronograph them. There is no measureable difference inspeed between them.

They both squirt out of the barrel at the around the same speed. That is a fact. No matter which chamber.

Now the 5.56, 62 grain is a different matter. You need to shoot it out of a 5.56 or Wylde chamber because of the throat is too short in a .223 chamber.

 

[pinshooter45]

It's about 2am and Im suffering from another of my frequent bouts of insomnia. Remebering what I learned from 'Tales of the gun" What gave the M16 it's original bad reputation was that the military wanted to switch the powder from stick to ball powder to increase FPS and long range they so dearly loved. Did a Quick search to find the info but was unsucsessful. but if memory serves the 5.56 Nato goes close to 3300fps and the civilain .223 is around 26-2700fps and that is the difference, which also changes chamber pressures ect. Probably already posted but for some reason the links would not connect before I posted and I think the Xanax is finally kicking in so I'll revist this tomorrow and see what else has been posted. I know I feel a little difference when I shoot .223 then switch to 5.56.

 

[Charlie2]

Ok.. well you just go ahead and shoot 5.56 thru your .223 rifle.. !! And I'll keep doing what I've been doing.. And I hope you will excuse me if I don't believe you..!! And as far as JUST reading the internet .. I don't just read the internet,, I have been shooting an AR for at least 20 years..!! Thanks ..

 

[mvician]

Sigh, there is no difference between the pressures of a 5.56 or 223 55 grain load

Now the 5.56, 62 grain is a different matter. You need to shoot it out of a 5.56 or Wylde chamber because of the throat is too short in a .223 chamber.

So you can measure chamber pressures?

What does the bullet weight have to do with it?
Why do they make .223 Remington in 77gr, 75gr, 69gr, 62gr, ect. ?
By your way of thinking these would all have to be shot out of a 5.56 chamber.

 

[sporter]

I bet when they switch production over from m193 federal to .223 American eagle at the factory its a matter of switching the packaging.
I am also willing to bet the cases are the same dimensional sans headstamp.

This 5.56 vs .223 argument is silly. Someone please post a link or proof of 5.56mm damaging a .223 rifle.

This reminds me of several years back when everyone on the net said you could not shoot .308 out a 762nato gun. Since then several manufactures have noted that their guns will shoot both safely.

The Russian Bear ammo is marked 7.62x51mm at the skid/pallet level but when you open it up the boxes are marked .308. I guess the Russians didn't get the memo from the internet experts.