In most cases yes. Rifles chambered in .308 Winchester can generally fire 7.62×51 NATO ammo, but the reverse is not always advised. Check your rifle manufacturer’s guidance.
Short answer
In most quality rifles, yes. Many shooters fire 7.62×51 NATO in .308 Winchester chambers.
Differences
- Chamber dimensions can differ slightly (NATO chambers are a bit longer in the throat).
- Pressure measurement methods differ. The two loads often run near the same pressure, though military loads can run higher in some lots.
- Headspace tolerance is looser in NATO chambers.
Safe practice
Check your rifle’s manual and the maker’s guidance. Using .308 in a 7.62 NATO rifle is generally accepted. NATO ammo in a tight .308 match chamber can raise pressure.
Ask
A gunsmith if unsure.
Why the question has a safety side
The 7.62x51mm NATO cartridge and the .308 Winchester share nearly identical external dimensions, and many rifles chambered in .308 Winchester will physically accept 7.62×51 ammunition. However, the two are loaded to different pressure standards and measured differently, so they are not formally interchangeable.
- SAAMI sets a maximum average pressure of 62,000 psi for .308 Winchester using piezoelectric measurement, while NATO 7.62×51 is tested using different methods (a copper crusher or transducer in specific positions), so numbers are not directly comparable.
- Chamber dimensions differ slightly; military chambers can have a longer headspace allowance and a different throat.
- Many manufacturers say shooting commercial .308 in a 7.62 NATO rifle is generally safe, while NATO ammo in some .308 rifles requires checking.
Practical guidance
Read the rifle manufacturer’s manual and the markings on the barrel, since some say “.308 Win” only. Do not rely on forum advice. If in doubt, have a qualified gunsmith inspect the rifle for headspace. Use ammunition in good condition from reputable manufacturers, and do not fire unknown surplus ammo. Gun safety rules apply at all times.
Why the question has a safety side
The .308 Winchester and 7.62x51mm NATO cartridges have almost the same external dimensions, but SAAMI sets the .308 Winchester maximum pressure at 62,000 psi while NATO specifications are measured differently and military loads can produce higher pressure in some cases. Chamber dimensions can differ slightly.
Practical guidance
Many modern rifles chambered in .308 Winchester accept commercial 7.62 NATO ammunition without problems, while firing .308 in some 7.62 NATO chambered firearms is also usually fine. Follow the rifle maker’s manual, and check headstamps. Do not use ammo if unsure. A qualified gunsmith can advise.
Specifications
SAAMI sets the .308 Winchester maximum average pressure at 62,000 psi, while the NATO 7.62x51mm is specified by CIP at about 415 MPa (about 60,200 psi) measured in a different way, so the pressures are comparable though measured by different methods. The chamber and headspace tolerances for 7.62 NATO may be slightly more generous.
What shooters should do
Follow the rifle manufacturer’s guidance and stamped markings. Rifles marked 7.62 NATO generally accept .308 Winchester cartridges, and many .308 rifles accept NATO ammunition though bolt thrust and primer differences are noted by some makers. If in doubt, ask a gunsmith or the maker before firing. Use only factory ammunition from reputable sources and safe handling practices.
Based on data from SAAMI and CIP
