A friend obtained a batch of ammunition built to 7.62×51 NATO specs. Differences from commercial .308 Winchester include
- full metal jacket bullets (not full actually, but open to the core at the base of the bullet hidden in the case, complying with the Geneva Convention against expanding bullets),
- gunk sealing the bullet in the neck to prevent ingress of moisture and to grip the bullet more tightly under handling and recoil,
- crimped primer preventing a loose primer jamming or exploding prematurely in machine-guns, and
- gunk around the primer sealing it against the ingress of water or oil.
Some of these features may reduce accuracy but the increase in reliability makes them worth it. A shooter with a bolt-action rifle may fire 10K rounds in a lifetime while a military shooter with a machine-gun may fire that many rounds in an afternoon. When it comes to life and death, increased reliability matters.
From the Geneva Conventions:
“Art. 16. In addition to the prohibitions which shall be established by special conventions, it is forbidden:
(1) To employ poison or poisoned weapons, or projectiles the sole object of which is the diffusion of asphyxiating or deleterious gases;
(2) To employ arms, projectiles, or materials calculated to cause unnecessary suffering.
Entering especially into this category are explosive projectiles or those charged with fulminating or inflammable materials, less than 400 grammes in weight, and bullets which expand or flatten easily in the human body, such as bullets with a hard envelope which does not cover the core entirely or is pierced with incisions.”
This kind of ammunition is useful for casual target-shooting but is not legal/desirable for hunting big-game because of the non-expanding bullets. Better bullets and accuracy can be obtained by choosing individual components of ammunition and reloading. Some 7.62×51 brass have Berdan primers not easily reloaded. Buyer beware…