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32-20 Winchester Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 32-20 Winchester with the free, in-browser MyLoads internal ballistics simulator. The figures below are illustrative estimates from a physics model — not a recommended load. Always cross-check a current published loading manual.

32-20 Winchester reference

Maximum average pressure (MAP)16,000 CUP
Nominal case capacity22.0 gr H₂O
Groove / bullet diameter0.314 in (7.98 mm)

Example simulation illustrative

Bullet
Hornady 0.312 100 gr XTP
Powder
IMR 4227
Charge
12.2 gr
Barrel
18.5 in

Muzzle velocity

1,678 fps

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

16,010 – 19,462 – 22,967 psi

MAP for this cartridge is specified as 16,000 CUP (CUP is not directly comparable to this psi estimate)

The simulator isn't optimized for this cartridge yet: there isn't enough published pressure data to check it.

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

Popular 32-20 Winchester powders

Powders and bullets handloaders commonly use for the 32-20 Winchester, drawn from public discussion and listed most common first. They appear as the Popular group in the calculator's pickers. This is not a load recommendation — always check your load against a current published manual.

Popular 32-20 Winchester bullets

Use MyLoads as a 32-20 Winchester 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 32-20 Winchester in the MyLoads calculator →

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