The numbers
- Manufacturer
- SIG SAUER
- Reticle
- BDC1
- Focal plane
- second focal plane
- Units
- MOA
- Magnification
- —
In the second focal plane the subtensions are only true at one magnification — check your manual for which, and dial there before you hold.
Reticle library · SIG SAUER
SIG SAUER BDC1
Drawn to scale from SIG SAUER’s own specification sheet, and checked mark by mark by a person. This is the same geometry Harson Ballistics draws your holdover on.
Drawn from SIG SAUER, Inc.’s published specification.
Scopes with this reticle
- TANGO-SPR 4-16x44
- TANGO-SPR 6-24x52
Other SIG SAUER reticles
Subtensions
SIG's TANGO-SPR manual p16, 'Units are in MOA at max magnification' (16x or 24x depending on the scope). Same sheet, same figures as the WHISKEY4 BDC1. Published: 0.25 crosshair; windage hashes every 2 MOA (callout 2), 1.50 long and 0.25 thick, drawn at 2/4/6/8 either side; hold marks below centre at 1.50, 3.75, 6.50 and 9.50, each 1.50 long and 0.25 thick; posts 2 MOA thick, starting 10 MOA left, right and above centre and 14.50 below. No marks above centre, no numerals. Not illuminated: SIG lists both TANGO-SPR BDC-1 scopes with 'Illumination: No'. The hold marks are a BDC: SIG does not state the load or ranges they are cut for, so the app treats them as plain MOA holds. Outer post ends are not dimensioned (the sheet stops them at 20 MOA and draws no field-of-view outline) and are run to the field edge as a display convention.
How this one was checked
Verified 8 Oct 2026 against specs/sig-sauer/25SIG3843_TANGO-SPR_Manual_7405579-01_R11.pdf page 16, read as vectors with pymupdf by tools/build_sig_sauer.py, which re-asserts every check on each build. scale 4.1483 pt/MOA from callout 10 (centre to top post tip); 40 published-callout edges then checked at that one scale, worst residual 0.009 MOA. The reticle is drawn twice on this page: a stroked outline and a set of loose filled rectangles over the posts. The fills are oversize and were ignored; the outline's centreline reproduces every callout. Checklist: cross with four posts, bottom post starting lower than the other three; windage hashes 2/4/6/8 both sides, centred on the line (equal above and below, so not one-sided); four hold marks below centre, centred on the vertical; no marks above centre; no numerals; no floating centre (the 0.25 lines run through); post tips square; every published figure (10, 14.50, 1.50, 3.75, 6.50, 9.50, 2, 1.50 x2, 0.25 x5 and the post thickness) lands on a drawn edge. Outer post extent is a display convention.
Use it on your own rifle
Harson Ballistics draws this reticle at your magnification with your holdover marked on it, from your rifle, load and conditions. Works with no signal and no account.
Subtensions are published by the manufacturer and reproduced here for reference. Confirm your own dope on a range before you rely on any of it. Harson.ai is not affiliated with SIG SAUER.