Thread: Shooting 556 in a 223

Originally Posted by grandpamac

Greetings All,
There are two factors at work here. .223 is loaded to a lower pressure of 55,000 PSI these days and the US load data now reflects this. 5.56 ammo is loaded to a pressure north of 60,000 PSI plus the 5.56 chamber is bigger than the .223 which will push the pressure higher. So it is generally regarded as unwise to fire 5.56 ammo in the .223 chamber. Most of the time you may get away with it but.
In his 1980 report on the .223 Ken Waters chronographed some Korean 5.56 55 grain ammo in his 24" Remington 700. The velocity was 3,421 fps, above any of his handloads some of which were pretty hot. Fast forward a bit and a packet of PMC .223 cartridges with 55 grain projectiles appeared in my cupboard. I chronographed them at well over 3,300 fps in my well used Brno. I just fished the box out. All of the primers are flat and badly cratered plus two of them are pierced. Two don't have primers. Three are unfired and won't be in my rifles.
GPM.

Funny how it's us old guys who urge caution. Part of me fancies staying quiet just to increase the odds of hearing from someone who finds themselves looking at a buggered expensive Tikka or somesuch. But nah, Im really not that mean....I just dont understand why anyone would take a decent rifle and put basically crap ammo in it. Maybe if you've got an old beater...I mean, is 5.56 really that much of a thing? I have a Ruger Ranch in 5.56 because I thought, great, it will eat anything. Never had any 5.56 to put thru it in what about 10 yrs. Probably cause I reload near everything but where do you even buy 5.56? And wouldn't it be mostly fmj? Perhaps its all the now redundant stockpiles hanging around post AR15 times....in which case buy a Ruger Ranch in 5.56 with some extra 10rd AR15 mags and keep the nice rifles for what they're intended. Yes?