Re: .308 Win and 7.62 NATO
This is a great discussion. The differences in military ball ammunition for use in the 7.62 Nato and the .30M1 and .30M2 for the Garand rifles. With the gas operated M1 Garand and the M1A/M-14 family of rifles, there is a major difference in useable powders between these and sporting rifles. The Garand in particular is designed for specific powders.
The gas system in the Garand limits useable powders because of the 'gas-port pressure curve". Author John C. Clark has explained this very well. While there are powders that can deliver outstanding accuracy in the .30-06, some are not acceptable for use with the Garand's gas system.
For years, the Government's arsenals used IMR-4895 and WC-852 powder for loading .30M1 (173 grain FMJ) and .30M2 (150 grain FMJ). The pressure curve delivered is acceptable for the Garand's gas system. Faster or slower burning propellants may cause damage to the operating rod.
In my bolt action rifles, I found that my most accurate hunting loads used IMR-4350. This powder is not useable in the Garand. Most commercial hunting ammunition is not designed with the operating pressures of the Garand or the M1A in mind.