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327 Federal Magnum Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 327 Federal Magnum 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.

327 Federal Magnum reference

Maximum average pressure (MAP)45,000 psi
Nominal case capacity20.5 gr H₂O
Groove / bullet diameter0.312 in (7.92 mm)

Example simulation illustrative

Bullet
Hornady 0.312 100 gr XTP
Powder
Accurate No. 9
Charge
11.7 gr
Barrel
4 in

Muzzle velocity

1,486 fps

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

27,685 – 41,263 – 58,934 psi

nominal is 92% of the 45,000 psi maximum average pressure

This sample load runs near the maximum average pressure for the 327 Federal Magnum (about 92% 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 is an estimate; always confirm your load against a current published manual before loading.

Use MyLoads as a 327 Federal Magnum 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 327 Federal Magnum in the MyLoads calculator →

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