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33 Winchester Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 33 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.

33 Winchester reference

Maximum average pressure (MAP)3,050 BAR
Nominal case capacity63.0 gr H₂O
Groove / bullet diameter0.338 in (8.59 mm)

Example simulation illustrative

Bullet
Hornady 0.338 200 gr FTX (Marlin Express)
Powder
IMR 3031
Charge
35 gr
Barrel
24 in

Muzzle velocity

2,136 fps

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

30,422 – 35,731 – 41,485 psi

nominal is 81% MAP (44,237 psi)

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 33 Winchester powders

Powders and bullets handloaders commonly use for the 33 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 33 Winchester bullets

Use MyLoads as a 33 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 33 Winchester in the MyLoads calculator →

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