Generating a sight tape on a calculator is only the first step. The tape was built on inputs — your speed estimate, your sight radius measurement — and any error in those inputs shows up as missed shots at distance. Before you trust a new tape on a hunt, you need to confirm it at the range with your actual bow, arrows, and shooting style.
This takes 20 minutes and three distances. Here's the drill.
Start at the distance your tape is zeroed at — typically 20 yards. Rangefind it precisely. Dial your sight to the 20-yard mark and shoot three arrows. They should group at your aim point. If they're consistently high or low, your zero needs adjusting before you can trust any other mark on the tape.
Move to roughly half your maximum distance — 40 yards on a 70-yard tape, 30 yards on a 60-yard tape. Dial to that exact yardage and shoot three arrows. A group within 2 inches of your aim point is acceptable. Errors start to reveal themselves at this distance. If you're consistently 3–4 inches off, your speed input is likely wrong.
This is where tape errors show up most clearly. Shoot at your maximum intended hunting distance — 60, 70, or 80 yards depending on your tape. If you're hitting 3 or more inches consistently low, your speed input was too high (regenerate with 5–10 fps less). Consistently high means your speed input was too low.
The most common cause of tape errors is inaccurate speed input. If your tape is consistently off in one direction at long range — always high or always low — adjust your speed by 5–10 fps and regenerate. It's free and takes under a minute at the generator.
Inaccurate speed estimate — the most common issue. A chronograph reading at your actual setup is always more accurate than an IBO-based estimate. If you haven't used a chronograph, prioritise getting one before season.
Sight radius measurement error — a quarter-inch mistake in your radius shifts all marks by a meaningful amount at 60+ yards. Re-measure at full draw and regenerate if you suspect this.
Printing at the wrong scale — if your tape printed at 95% instead of 100%, every mark is physically in the wrong place by a consistent percentage. Reprint at exactly 100% and reinstall.
Cold weather — arrows slow down in cold conditions by 5–10 fps compared to warm weather. A tape verified in summer may run slightly long in cold hunting conditions. Consider this when hunting in significantly different temperatures than when you verified.
Regenerate the tape if your speed or radius inputs were wrong. Small consistent errors at distance always trace back to one of these two numbers. Adjust your zero (not regenerate) if your 20-yard mark is slightly off — this is a bow sight calibration issue, not a tape issue. Once zero is confirmed, if marks at distance are still off, it's the tape.