JoAT Ballistic Tape Maker

Load

Use your chronographed velocity; it matters more than anything else here.

No chronograph? Estimate velocity from barrel length

Enter the velocity printed on the ammo box and both barrel lengths.

Rifle

Atmosphere

Leave pressure blank to estimate it from altitude. A tape is only right near the conditions it was built for.

Predict conditions for a place and date

Ranges
Turret

Tape length is π × (diameter + tape thickness), so the ticks line up once the label wraps. Vinyl label stock is about 0.08 mm.

Stick the plain tail end down first, wrap toward the UP direction, and finish with the zero end on top. Line its edge up with the two small marks so the overlap only covers blank tape.

Layout, top to bottom: range numbers, tick marks, click numbers. Direction is as seen from behind the scope with the tape wrapped on. Most caps that turn counter-clockwise for UP need right → left. Check against the UP arrow on your turret.

Tape preview

Print / Save PDF builds a Letter page with three copies of the tape, a 50 mm check bar and your dope. On iPhone it opens the share sheet: pick Print. On a computer it saves the file (Chrome and Edge let you pick the folder). Measure the bar after printing; if it isn't exactly 50 mm, the page was scaled.

Dope card

Standard US business card, 2 × 3.5 in, printed upright at true size next to your dope table. Colors follow the tape colors. Wind is a 10 mph full-value crosswind; spin drift appears once twist and bullet length are set.

Dope

RangeDrop (in)MOAClicks10 mph windSpin drift (in)Drift MOAVel (fps)Energy (ft·lb)TOF (s)

Targets

Eight 4 × 6 in targets with a ¼" grid. Print at 100% / Actual Size on 4 × 6 photo or index stock, or on Letter paper and trim. Tap a target to view it, or save or print one at a time.