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338 Ruger Compact Magnum Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 338 Ruger Compact Magnum 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.

338 Ruger Compact Magnum reference

Maximum average pressure (MAP)65,000 psi
Nominal case capacity76.0 gr H₂O
Groove / bullet diameter0.338 in (8.59 mm)

Example simulation illustrative

Bullet
Hornady 0.338 200 gr SST
Powder
Hodgdon Varget
Charge
50.8 gr
Barrel
20 in

Muzzle velocity

2,461 fps

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

39,759 – 48,116 – 57,236 psi

nominal is 74% MAP (65,000 psi)

The simulator isn't optimized for this cartridge yet and may read pressure low.

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

Popular 338 Ruger Compact Magnum powders

Powders and bullets handloaders commonly use for the 338 Ruger Compact Magnum, 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 338 Ruger Compact Magnum bullets

Use MyLoads as a 338 Ruger Compact 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 338 Ruger Compact Magnum in the MyLoads calculator →

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