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38 Super Automatic +P Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 38 Super Automatic +P 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.

38 Super Automatic +P reference

Maximum average pressure (MAP)36,500 psi
Nominal case capacity17.5 gr H₂O
Groove / bullet diameter0.355 in (9.02 mm)

Example simulation illustrative

Bullet
Hornady 0.355 147 gr FMJ-RN-BT
Powder
IMR 800-X
Charge
4.9 gr
Barrel
5 in

Muzzle velocity

928 fps

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

20,648 – 24,031 – 27,559 psi

nominal is 66% of the 36,500 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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