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8.6 Blackout Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 8.6 Blackout (8.6 BLK) 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.

8.6 Blackout reference

Maximum average pressure (MAP)62,000 psi
Nominal case capacity51.0 gr H₂O
Groove / bullet diameter0.338 in (8.59 mm)

Example simulation illustrative

Bullet
Sierra 338 Caliber (.338) 300 gr HPBT MatchKing
Powder
Hodgdon Cfe Blk
Charge
16 gr
Barrel
12 in

Muzzle velocity

1,054 fps

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

16,041 – 18,325 – 20,516 psi

nominal is 30% 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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