CPR vs Spreadsheet: When the Numbers Move on You
Cost per round (CPR) is one of the four reasons people start handloading in the first place. The math is simple enough to fit on a napkin, and the savings are real. So why is it that almost every serious handloader ends up rebuilding the same Excel sheet from scratch, usually twice?
Because the numbers move. Component prices change every time you buy. Brass life depends on how aggressively you size. The bullet count in the box is sometimes 100, sometimes 250. Your old spreadsheet from 2022 still says primers are $35 a sleeve. The math is right; the inputs are wrong.
This page is about why CPR is worth tracking, why spreadsheets quietly fail at it, and what to do instead.
The Four-line CPR Formula
For each round you load:
- Bullet cost = bullet box price ÷ count
- Powder cost = powder can price ÷ (7000 ÷ charge weight in grains)
- Primer cost = primer sleeve price ÷ sleeve count
- Brass cost = brass lot price ÷ (lot count × expected firings)
Round cost = sum of those four.
That's it. Every line is a multiplication or a division. There is no advanced spreadsheet magic; the formula fits on a sticky note.
What an Excel CPR Sheet Looks Like
The classic handloader spreadsheet has rows for each cartridge and columns for each input. A typical 6.5 Creedmoor row might read:
| Component | Price | Per-unit | Per-round |
|---|---|---|---|
| Bullet (140gr ELD-M) | $52 / 100 | $0.52 | $0.52 |
| Powder (H4350) | $310 / 8 lb | $0.0055/gr | $0.232 (at 42.0 gr) |
| Primer (large rifle) | $90 / 1000 | $0.090 | $0.090 |
| Brass (Lapua, 6 firings) | $76 / 100 | $0.76 | $0.127 |
| Total CPR | $0.969 |
That's a real-looking sheet. It tells you the round costs about 97 cents loaded. Compared to factory match ammo at $2.50 a round, you're saving $1.50 a shot.
Then six months pass. You buy a new can of H4350 for $340 because powder prices went up. You discover Lapua brass is good for 8 firings if you neck-size, not 6. You start using a different primer brand. You're shooting a different bullet weight in the new barrel.
If you remember to update the spreadsheet, it works. If you don't, and most people don't, the CPR number on the sheet is fiction. You think you're loading at $0.97 a round. You're actually loading at $1.04. The error compounds across thousands of rounds.
Where Spreadsheets Quietly Fail
- Component prices drift. Every primer/powder/bullet purchase changes the inputs. The sheet only updates if you remember to change it. Most people don't.
- Brass life is per-lot, not per-cartridge. Your Lapua lot might last 10 firings; your Hornady lot 5. A single "expected firings" cell can't capture this.
- You can't recompute on the fly. You're at a gun show, you see a deal on primers, you want to know your new CPR with that primer. The spreadsheet is on your home computer.
- Sharing is a screenshot. Your buddy asks how you got 9mm down to 11 cents a round. You take a screenshot. He squints at it.
- Cross-load comparison is a pivot table. You want to compare CPR across your three favorite recipes. That's another spreadsheet, or a manual lookup, or a mental calculation.
None of these are dealbreakers. Spreadsheets work. They just leak accuracy slowly until you trust them less than you used to.
What an App Does Differently
A real reloading log app stores component prices on the components themselves, not in a separate sheet. When you buy a new can of powder at a different price, you update one record: every recipe that uses that powder recalculates automatically.
Brass life lives on the brass lot, not the cartridge. If your Lapua lot is on firing 7 of 10 and your Hornady lot is on firing 4 of 6, both numbers feed into their respective recipes' CPR calculations.
Comparing recipes is a tap. Sharing a recipe with its true CPR is a tap. Recomputing CPR for a hypothetical price is a tap.
This is what BrassTracker does. The Components tab holds your prices. The Brass tab holds your lots and firing counts. Every load recipe shows live CPR, recalculated whenever any input changes. You don't maintain a spreadsheet; you record the components you bought and the loads you developed, and the math comes out the back.
The Honest Comparison
| Spreadsheet | BrassTracker | |
|---|---|---|
| Initial setup | 30 minutes for a good template | Tap to add components |
| Keeping component prices current | Manual; easy to forget | Update once, recalculates everywhere |
| Per-lot brass life | Custom formulas | Built in |
| Cross-recipe comparison | Pivot or manual | Tap to compare |
| Sharing a recipe | Screenshot | One-tap link |
| Cost | Free | $2.99 once |
| Where it lives | A computer | Your phone |
| Survives losing the file | Maybe | Yes (iCloud sync) |
If you already love spreadsheets and have one that works, keep it. CPR is CPR; the formula is the formula. But if you've ever stared at an old spreadsheet and wondered whether the prices are still right, the answer is: probably not. And the fix is not a better spreadsheet.
Try BrassTracker
BrassTracker is $2.99 once - yours to keep. CPR is built in. Component prices live on components. Brass life lives on lots. Your math always reflects what you actually own. No cloud lock-in.