9 x 18 (9 x 18 Ultra, 9mm Police) is one of 607 cartridges supported by the IBC calculator. Pick a load from your reloading manual, enter it, and the calculator predicts velocity and peak pressure, then gives a verdict against the cartridge's pressure ceiling. It is a comparison tool for working between loads you already trust, not a source of load data.
| Max average pressure | 1,800 bar ≈ 26,100 psi |
|---|---|
| Case capacity (water) | 12.7 gr H₂O (0.82 cm³) |
| Case length | 18.0 mm (0.709″) |
| Max overall length | 25.5 mm (1.004″) |
| Bore diameter | 9.020 mm (0.355″) |
| Standard | CIP |
Catalogued reference values the calculator works from. No charge, velocity, or pressure data appears on this page; loads come from your manual.
9 x 18 (9 x 18 Ultra, 9mm Police) is fully supported in the calculator, but the current published validation corpus has no 9 x 18 (9 x 18 Ultra, 9mm Police) loads in it yet, so IBC prints no per-cartridge accuracy figure here. Per-cartridge numbers on this site appear only where the corpus actually contains loads for that cartridge. The corpus-wide results and the method behind them are on the methodology page.
Open the calculator, pick 9 x 18 (9 x 18 Ultra, 9mm Police) from the cartridge list, and enter a load from your current reloading manual. Compare variants: bullet weights, powders, charge steps. Start 10% below the manual's maximum charge and work up, watch the verdict on every rung, and check real pressure signs at the bench. The free tier covers single-load predictions and the first steps of a work-up ladder; PRO unlocks the full ladder and the charts.
Open the calculatorAccuracy figures on this page were computed from the published-manual validation corpus (9796 loads across 155 cartridges) with engine v1.1.14 (corpus build da7ac091). Page generated 2026-11-11. Method and provenance: methodology & accuracy.