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38 Special Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 38 Special 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 Special reference

Maximum average pressure (MAP)17,000 psi
Nominal case capacity23.5 gr H₂O
Groove / bullet diameter0.355 in (9.02 mm)

Example simulation illustrative

Bullet
Hornady 0.357 110 gr XTP
Powder
IMR Hi-Skor 700-X
Charge
4 gr
Barrel
4 in

Muzzle velocity

914 fps

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

13,873 – 15,444 – 17,083 psi

nominal is 91% of the 17,000 psi maximum average pressure

This sample load runs near the maximum average pressure for the 38 Special (about 91% of MAP at the nominal estimate; the upper interval can exceed it). It is shown only to illustrate the simulator — reduce the charge and work up from your manual's start load.

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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