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How Accurate Is Our Ballistic Engine?

Audit date: July 12, 2026. We tested our G1 trajectory engine against manufacturer-published drop tables at identical inputs (published muzzle velocity and BC, the table's stated zero, 1.5" sight height, standard atmosphere). Across 8 supersonic centerfire loads from Federal, Hornady, Remington, and Winchester (BC .314–.646), predicted drop matches the published tables within 0.31 MOA at every published distance and 0.11 MOA at 500 yards. The engine uses the standard published G1/G7 drag tables with a purely physical drag scale — no fitted corrections — so every table here is an out-of-sample test. Rimfire (.22 LR), the transonic regime where drag models are hardest to get right, matches CCI's published table within 0.09 MOA on drop and 4 fps on velocity at 100 yards. Note that manufacturer tables are themselves calculated from chronographed velocities and published BCs — this comparison proves our solver agrees with the industry references; your rifle will still differ from any table, which is what the range card builder's DOPE truing is for.

Federal GM308M .308 168gr SMK

2650 fps · G1 BC 0.462 · 200 yd zero · source: federalpremium.com GM308M

Federal GM308M (100yd zero)

2650 fps · G1 BC 0.462 · 100 yd zero · source: federalpremium.com GM308M

Hornady Match .308 168gr ELD-M

2700 fps · G1 BC 0.523 · 200 yd zero · source: hornady.com 80966

Hornady 6.5 CM 140gr ELD-M

2710 fps · G1 BC 0.646 · 200 yd zero · source: hornady.com 81500

Federal Power-Shok 30-06 180gr

2700 fps · G1 BC 0.385 · 200 yd zero · source: federalpremium.com 3006B

Remington Core-Lokt 30-06 150gr

2910 fps · G1 BC 0.314 · 200 yd zero · source: remington.com R30061

Winchester Super-X .270 130gr

3060 fps · G1 BC 0.372 · 200 yd zero · source: Winchester Super-X catalog

Hornady PH 7mm RM 162gr ELD-X

2975 fps · G1 BC 0.631 · 200 yd zero · source: hornady.com 80636

CCI Mini-Mag .22 LR 40gr (rimfire)

1235 fps · G1 BC 0.13 · 100 yd zero · source: cci-ammunition.com 0030

Beyond 500 yards

Published factory tables stop at 500 yards, so we extended the check ourselves for the long-range table on the cartridge pages. At identical inputs, our numerical solver closely matches reference calculations that far out: against reference G1 calculators (6.5 Creedmoor, 6.5 PRC, .300 PRC) our come-ups agree to within 0.1 MOA at 1,000 yards, and against Applied Ballistics' published firing-test data for the Berger .308 155-grain VLD our numbers land within ~2 inches of their G1 computation. That validates the calculation path, not an exact downrange prediction for a particular rifle. The G1 model itself has limits we won't hide: that same firing test shows a G1 prediction differs from measured reality by about 1 MOA of drop and ~7% of wind at 1,000 yards for a supersonic bullet — a combination of the G1 reference shape mismatching modern low-drag bullets and manufacturers' advertised G1 BCs running optimistic (the measured BC cut the drop error to ~0.4 MOA in that test; we compute from advertised BCs, so ~1 MOA is the honest expectation). The gap grows quickly through the transonic transition (marked amber on the tables) — we measured our engine reading ~5 MOA more drop than a Federal-sourced table for a .308 168-grain load going transonic near 1,000 yards. Treat the extended table as a solid first-round reference to ~1,000 yards for supersonic loads, and the amber transonic/subsonic rows as rough estimates to confirm with measured dope.

The G7 drag model

For loads that carry a measured G7 BC (about 250 in our database, concentrated in the long-range cartridges), the calculator, extended-ballistics view, and range card builder now compute with the standard G7 drag function instead of G1 — those surfaces show a G7 badge when it's in use. Our G7 path is the published standard drag table with a scale constant derived purely from physics (no curve-fitting), and it reproduces Applied Ballistics' firing-test trajectory for the Berger .308 155-grain VLD (G7 BC .228, 3,000 fps) at 1,000 yards to within 0.3 inches of drop, 0.4 inches of wind drift, and 0 fps of retained velocity against their measured-BC computation. G7 references the boat-tail shape of modern low-drag bullets, so its BC stays nearly constant across the supersonic range (Litz measured under 2% variation for that bullet, versus over 12% referenced to G1) — which is why the same advertised number predicts better at distance. The stored 500-yard tables on cartridge pages remain G1-computed against manufacturer references; transonic rows stay estimates under any standard drag model.

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