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300 Remington Ultra Magnum Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 300 Remington Ultra 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.

300 Remington Ultra Magnum reference

Maximum average pressure (MAP)65,000 psi
Nominal case capacity110.0 gr H₂O
Groove / bullet diameter0.308 in (7.82 mm)

Example simulation illustrative

Bullet
Hornady 0.308 200 gr ELD-X
Powder
Hodgdon H1000
Charge
85.9 gr
Barrel
26 in

Muzzle velocity

2,837 fps

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

43,972 – 54,060 – 65,423 psi

nominal is 83% of the 65,000 psi maximum average pressure

This sample load runs near the maximum average pressure for the 300 Remington Ultra Magnum (about 83% 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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