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300 AAC Blackout Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 300 AAC Blackout 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.

300 AAC Blackout reference

Maximum average pressure (MAP)55,000 psi
Nominal case capacity26.5 gr H₂O
Groove / bullet diameter0.308 in (7.82 mm)

Example simulation illustrative

Bullet
Hornady 0.308 150 gr GMX
Powder
Accurate A-1680
Charge
15.4 gr
Barrel
16 in

Muzzle velocity

1,555 fps

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

17,651 – 21,700 – 26,130 psi

nominal is 39% of the 55,000 psi maximum average pressure

Illustrative example — every figure is an estimate; always confirm your load against a current published manual before loading.

Use MyLoads as a 300 AAC Blackout velocity and pressure calculator: it estimates muzzle velocity, muzzle energy and the full chamber-pressure curve for your own powder, charge and barrel length, compared against the reference facts above.

Open the 300 AAC Blackout in the MyLoads calculator →

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