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45-70 Government (Lever tier) Load Data & Ballistics Calculator

Estimate chamber pressure and muzzle velocity for the 45-70 Government (Lever tier) 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.

45-70 Government (Lever tier) reference

Maximum average pressure (MAP)40,000 psi
Nominal case capacity81.0 gr H₂O
Groove / bullet diameter0.458 in (11.63 mm)

Example simulation illustrative

Bullet
Barnes .458 250 gr TSX FB
Powder
ADI Ar2219
Charge
53.3 gr
Barrel
24 in

Muzzle velocity

2,078 fps

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

19,339 – 25,286 – 32,112 psi

nominal is 63% of the 40,000 psi maximum average pressure

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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