Good Morning 2aHawaii Crew,

I was looking into an IWI Tavor in 5.56, more like fantasizing for now; my understanding is that you can shoot .223 in a 5.56 but not a 5.56 in .223 caliber rifles. Can you use the same p-mag for either caliber though or do I need to get mags for each caliber?  I will probably shoot .223 mostly but like the idea of being able to shoot hotter if I would like too.

I am new to firearms but have been bitten hard by the enjoyment of shooting so sorry if this is a remedial question.

Many thanks!

.223 REM and 5.56 NATO use the same magazines. The biggest difference between the two is that 5.56 is loaded to higher pressure's. Physically they appear almost identical.

P-mags can take both the 5.56 and .223 ammo. 

.223 REM and 5.56 NATO use the same magazines. The biggest difference between the two is that 5.56 is loaded to higher pressure's. Physically they appear almost identical.

There are some minor dimensional differences on the casing as well including but not limited to wall thickness.  I will also add that the 5.56 NATO is allowed to be loaded to higher pressures than a .223 Rem it doesn't neccesarily mean it is.

Thanks Fellas, as always I can find a wealth of info here

basically, a 5.56 chamber can take both 5.56 & .223, but with a .223 chamber (tighter tolerances), shooting 5.56 is not recommended.  Both 5.56 and .223 uses the same mags.

This may not seem relevant to your question, but you can also use the same Pmags that fit 5.56X45 and .223 for the 300 Blackout caliber. Just in case you ever wanted to shoot a 30 caliber round from an AR platform w/out having to buy .308 or 7.62X51.

This may not seem relevant to your question, but you can also use the same Pmags that fit 5.56X45 and .223 for the 300 Blackout caliber. Just in case you ever wanted to shoot a 30 caliber round from an AR platform w/out having to buy .308 or 7.62X51.

I was just about to point this out.  Same goes for 6.8SPC and 6.5 Grendel.

Did not know that about the 6.8 SPC and 300 Blackout all fitting in the PMags.

Thanks! Makes my quest for my first AR even more justifiable 

Did not know that about the 6.8 SPC and 300 Blackout all fitting in the PMags.

Thanks! Makes my quest for my first AR even more justifiable 

Once you got the mil-spec lower, you can put on any upper you like.  That's one thing good about ARs, they are like legos for guys.  No need to go ffl for the upper only

it works, just dont be shooting a 5.56 round out of a .223 rifle. then you will have complications... it may fire but it will blow eventually...