Where every number on your screen came from, in plain words. Nothing here changes a load — it tells you how much weight to put on one.
Looking for how to use a screen? The Freebore manual walks through every one.
Something wrong, or a number you don't trust? Write to support@freebore.app.
Want your account gone? How to delete your account, with or without the app.
Two kinds of number share those tables, and each cell says which it is. Upright is book data — a manual's own charge, read straight off the page and interpolated only inside that manual's own start and max. Nothing of ours touches it. Slanted orange is ours: no laboratory fired it, and no manual printed it. We run it at that cartridge's case capacity, that bullet's length and its pressure ceiling. Verify it against a current manual before you load it.
A row gets a max charge — a stop line — only when the powder's pressure has been checked against real measured pressure. Speed is easier: every powder we hold constants for can be run for speed, so every one of them gets a row. Where a powder has speed and no measured pressure, the row says no max instead of quietly leaving the space blank. That is a gap in what anyone has published, not a warning about the powder — get the ceiling from the powder maker's own data for your cartridge.
The ‹ and › marks are not missing data. They mark where a row ran out — too little powder to fill the case, too much to fit it, or past the charges that powder's data was ever measured over. Tap one and it tells you which.
Where our start charge comes from. When we work out a starting charge ourselves, we set it at 9.94% below the max — max × 0.9006. That is measured, not a rule of thumb: it is the median of 32,439 published start-and-max pairs across 286 cartridges from 40 sources on file here. Publishers vary by about 3.17 percentage points either side of it, so treat our start as a normal starting charge, not a precise one. Start low, work up, watch for pressure signs.
Some bullets get skipped with no row at all, and the table lists each one. Usually it is one of two things: the bullet is a manual's own description that matches nothing in our catalogue, so we don't know its length; or it does not make a round at that seating length in that case. Length sets how deep the bullet sits, seating depth sets pressure, and we never work a length back from a weight — so we print nothing rather than a number built on a guess.
Beside a load you'll see close match, fair match, little data or not checked. Every one of those is about US — how our numbers compare with the published loads for that exact cartridge, powder and bullet weight. None of them is a grade on the load, which is the manual's, and none is a promise about your rifle.
More published loads does not mean a better match, and fewer does not mean a worse one — the wording tells you how much CHECKING there was, separately from how close we came. Your chronograph is the final word on both.
A max charge is the charge at which our numbers reach that cartridge's pressure ceiling — the SAAMI or C.I.P. maximum where one is registered, or, for a wildcat nobody ever registered, the parent case's ceiling, said in those words. It is not a figure any laboratory fired. Work up to it. Never start at it.
The band beside it — "50.2–53.6 gr" — is the honest width of that answer. It comes from how far that powder's own measured pressures spread, so the single number is the middle of a range, not a promise. Where a powder has no measured pressure at all, no max is offered and the screen says so rather than extrapolating one.
"Calibrated" means we corrected our number. For a powder in a cartridge where enough loads have been published, we compare our pressure against those published loads and shift ours to match, then say by how much and against how many loads. Where that correction rests on only one or two powders in a cartridge, the screen says "treat as rough". A moved number that doesn't say it moved is exactly what the label exists to prevent.
Copper-crusher cartridges (CUP) get no percentage of maximum. Copper crusher and modern transducers are different measuring methods, not different units, and there is no honest conversion between them — so we show none instead of a made-up one.
Open a cartridge in Workup and its load data is kept on this device automatically, so the app still works at the range with no signal. Cartridges used by your saved rifles are topped up quietly whenever you do have a signal. It is a few megabytes, it costs you nothing, and clearing it only means the next open needs a signal.
Your own saved work — rifles, loads, sessions, notes, groups — is a different thing: it syncs to your account and is not what this list is about. See the Privacy page for where that lives.
Verified means two numbers the maker published, checked against each other. Drawn means the maker's own picture, scaled by one number they published and not checked a second way — every one says so on the glass. The rest are still being read off the makers' own documents and appear as they pass.
If your reticle is on screen without the verified mark, the holds it draws are as good as the one number behind them. Check a hold against your own dial before you trust it at distance.
Truing changes one number so your come-up lands where your hits did: the speed, the drag (a percent on the BC), or a drop scale for the slow end of the flight. It never touches your zero, your air or your scope. Those are yours to get right first, because a truing on a wrong input bakes that error into every come-up after it.
Why it matters which one you true. Any of the three will put you on at the distance you shot. Past it they part company, and the wrong one gets worse the farther you go. So the rule is: speed if no chrono ran while you shot the string, drag if one did, and a drop scale only for hits where the bullet has slowed under Mach 1.2. When speed and drag both fit your hits, the result shows the two side by side, with what each does at 1.5 times your farthest hit, before you apply either.
Where to true. Between two distances worked out for your load. Too close and a 1% speed error hides inside 0.1 mil, one click. Too far and the bullet is under Mach 1.2, slowing toward the speed of sound, where flight gets erratic. A subsonic load (under 1,100 fps at the muzzle) has no far end, and drag barely moves it, so drag is never the pick there.
The scope tracking test is gone. Most modern scopes track, and the test confused more shooters than it helped. What's left is a tick on the rifle, Scope tracking checked, with the date: a reminder to confirm your scope dials what it says before you true. It changes no number, and a tracking figure saved on a rifle before is no longer used. A correction you can't see or re-test has no business moving your come-up.
Which buttons to press, in order: the manual's True it section.
Every number Freebore predicts — pressure, speed, drop, wind — is an estimate from a model and published data. It is not a pressure gauge and it is no substitute for one. Work up from a current published starting charge, watching for pressure signs as you go. You are responsible for every round you load and fire.