Quoted:
as long as the gun is 5.56 and NOT .223 it will eat any ammo.
View Quote
???? Excuse my ignorance but I thought they were on in the same????
View Quote
They are not quite the same as discussed in this SAAMI Tech Bulletin:
SAAMI
SPORTING ARMS AND AMMUNITION MANUFACTURERS' INSTITUTE, INC.
Technical Office
P.O. Box 338
Branford, CT 06405-0338
With the appearance of full metal jacket military 5.56 ammunition on the
commercial Market, it has come to the attention of the Sporting Arms and
Ammunition Manufacturers' Institute (SAAMI) that the use of military 5.56 mm
ammunition in sporting rifles chambered for Cal. 223 Remington cartridges can
lead to higher-than-normal chamber pressures and possible hazards for the
firearm, its user and bystanders.
Tests have confirmed that chamber pressures in a sporting rifle may be
significantly higher in the same gun when using military 5.56nm ammunition
rather than commercially loaded Cal. 223 Remington cartridges, according to
SAAMI.
SAAMI points out that chambers for military rifles have a different throat
configuration than chambers for sporting firearms which, together with the full
metal jacket of the military projectile, may account for the higher pressures
which result when military ammunition is fired in a sporting chamber.
SAAMI recommends that a firearm be fired only with the cartridge for which it
is specifically chambered by the manufacturer.
Issued -January 31, 1979