IBC is a physics-based interior ballistics calculator that runs in your browser. Pick a load out of your reloading manual, type it in, and it predicts velocity and peak pressure, rates the load against the cartridge's pressure ceiling, and draws the pressure curve behind it. It computes trajectory and drop, keeps a logbook of the loads you save, and prints a range checklist for the work-up ladder. Nothing to install; it works on a phone at the bench.
The part we think matters most: IBC checks itself against a corpus of thousands of published loads from printed reloading manuals, and it publishes the error rates, overall, per powder, and per cartridge, with the method and provenance next to the numbers. When the calculator says a load reads a few percent under your manual's velocity, you can look up how wrong predictions like that one usually are, and what they are good for: comparing loads against each other, not guaranteeing any single shot. No other simulator we know of publishes comparable numbers.
| What a reloader needs | IBC free tier, PRO $17.99/mo |
QuickLOAD / QuickTARGET $174.95, Windows disc |
GRT was free desktop |
LoadData.com $34.95/yr |
4DOF, ShootersCalculator free |
|---|---|---|---|---|---|
| Predicts velocity and pressure for a load | Yes | Yes | Yes | No, it serves published loads | No |
| Verdict against the pressure ceiling, per load | Yes | No | Partial | Not applicable | No |
| Work-up ladder with a verdict per step | Yes | Manual | Yes | Published min/max only | No |
| Publishes its own error rates | Yes | No | No | No | No |
| Trajectory and drop tables | Yes | Yes, QuickTARGET | No | No | Yes |
| Load logbook | Yes | Files on your disk | Yes | Saved searches | Favorites |
| Chronograph calibration | No | Yes | Yes | No | No |
| Print / export | Printable checklist | Reports, XML | Site features | Printable charts | |
| Runs in a browser, phone included | Yes | No | No | Yes | Yes |
Competitor cells come from each vendor's own public materials (neconos.com, grtools.de, loaddata.com, hornady.com, shooterscalculator.com), current as of November 2026. We make no claims about their internals.
QuickLOAD's cartridge library is much bigger than ours, 1,200-plus cartridges against our 607, and it has wildcat cartridge design and chronograph interfaces. Those are real capabilities. If your workflow depends on them, QuickLOAD earns its price and IBC is not there yet.
GRT had a large community-fed powder set and tools like its OBT calculator. But its author died in 2022, and in July 2026 the grtools.de site posted that downloads were removed and bugs would no longer be fixed. Copies still circulate; new users can no longer get it.
LoadData.com is a different kind of tool: an archive of over 317,000 published loads from the Handloader and Rifle magazines. We do not publish loads at all. You bring a load from your current manual, enter it, and IBC predicts how it behaves; that keeps the comparison tool framing honest.
The free trajectory apps, Hornady 4DOF and ShootersCalculator, handle exterior ballistics well. They do not predict chamber pressure or velocity for a hand load, and they give no safety verdict on a charge.
IBC is a comparison tool, not a load table. It does not publish loads: start from a load in a current reloading manual, enter it, and compare. Start 10% below the maximum charge and work up.