222 mag

[nilebartram]

I have a question. Is 22 mag close to .223 or 5.56? nilebartram

 

[Mark M.]

Yes, in fact that's mostly why the 222 mag went away

 

[jepp2]

I have a question. Is 22 mag close to .223 or 5.56?

Are you asking about the 222 Rem Mag cartridge? Per SAAMI (and I have the chamber/cartridge drawings below):
223 Rem 55K PSI max, 28.8 gr WC
222 Rem Mag 58.7 PSI max, 30.5 gr WC
5.56 Nato 62.4K PSI max (measured differently than 223 however) 28.5 gr WC

The 222 Rem Mag has a much longer case neck than the 223 and a slightly higher max pressure rating. The 5.56 chamber has a different throat than the normal 223 chamber.

Don't know if that really addresses your question. The 222 Rem Mag was the parent case for the 204 Ruger cartridge.

 

[nilebartram]

I was thinking the 222 mag was the parent case for the 5.56. Thanks for the responce. nilebartram

 

[MagnumManiac]

All of those cases were born from the 222Rem, just made longer.
The 223/5.56 won the US Army over, which made the 222RemMag a factory offering that died out.
I had one of the original Sako L461 Vixen Deluxe models from 1970/71 in 222Mag, great cartridge, but when brass was no longer available, stupidly, I sold it.
Still have it’s sister in 222Rem.
The performance between the 223 and 222Mag are very similar with the 222Mag winning by a small but definite margin.
I run my 222 to match the larger 223 without issue.

Cheers.

 

[Oso]

I was thinking the 222 mag was the parent case for the 5.56. Thanks for the responce. nilebartram

.222 Remington was parent to the .222 Rem. Magnum, and also the basis for creation of .223 Remington. In 1960's the .222 Rem. Magnum was developed for potential selection as new military cartridge, but the 5.56 cartridge won out for the M16 rifle and NATO.

Due to large case volume (5%-10%), the .222 Rem. Magnum has more power then .223 Remington. By comparison the .223 Remington Ackley Improved (.223AI) is comparable to .222 Rem. Magnum in case volume. The power difference is 100-150 fps shooting a 55gr bullet.

Edit - Common minds think alike ...MagnumMania read my mind and hit Post faster!

The 204 Roger is basically the .222 Rem. Magnum case.

 

[JohnKielly]

My recollection was that the .222 Mag was the calibre proposed by the military for their new rifle, but during the trials period, Remington patented it, so the military created the .223. Could be wrong with that recollection.