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308 Winchester Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 308 Winchester with the free, in-browser MyLoads internal-ballistics simulator. The figures below are illustrative estimates from a physics model — not a recommended recipe. Always cross-check a current published loading manual.

308 Winchester reference

Maximum average pressure (MAP)62,000 psi
Nominal case capacity56.0 gr H₂O
Groove / bullet diameter0.308 in (7.82 mm)

Example simulation illustrative

Bullet
Hornady 0.308 190 gr InterLock BTSP
Powder
Winchester W760
Charge
37.5 gr
Barrel
22 in

Muzzle velocity

2,058 fps

Peak chamber pressure (interval, ±10% burn-rate)

25,402 – 34,495 – 44,838 psi

nominal is 56% of the 62,000 psi maximum average pressure

Illustrative example — every figure here is an estimate and can be wrong. Always consult a current published loading manual, and never trust these numbers on their own.

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