Zeroing Your Rifle Scope at 100 Yards — UK Guide

Zeroing at 100 yards is the most common baseline for centrefire rifles in the UK, whether you are stalking deer across Scottish hillsides, controlling foxes on farmland, or punching paper at your local Home Office–approved range. A solid 100-yard zero gives you a practical reference point from which you can calculate holdover or dial corrections for longer shots, and it keeps your point of impact close to your point of aim inside the distances where most UK shooting actually happens — typically out to around 200–250 yards for stalking, and further for target disciplines.

Getting there reliably, however, depends on understanding your scope's adjustment system, parallax settings, and reticle type. A scope with 1/4 MOA clicks moves point of impact by roughly a quarter of an inch per click at 100 yards (since 1 MOA ≈ 1.047 inches at that distance). A 0.1 MRAD (mil) scope moves point of impact by 1 cm per click at 100 metres — which is effectively 0.36 inches at 100 yards. Knowing which system your turrets use before you start saves ammunition, frustration, and daylight.

This guide walks you through the complete process — from bore-sighting at 25 yards to confirming your group at 100, choosing the right scope features, and avoiding the parallax and FFP/SFP pitfalls that catch out even experienced shooters. We have also picked a handful of scopes that make the zeroing process especially straightforward thanks to features like exposed zero-stop turrets, side-focus parallax, and clearly defined MRAD or MOA reticles.

Buying Advice

When choosing a scope with a clean 100-yard zero in mind, prioritise repeatable, tactile turret clicks. Exposed turrets with a zero-stop mechanism let you dial up for longer shots and return to your 100-yard zero by feel alone — invaluable in poor light or when wearing gloves during a winter fox outing. Look for turrets that match the reticle unit: an MRAD reticle paired with MRAD turrets (or MOA with MOA) eliminates on-the-fly conversion maths and reduces the chance of dialling errors.

Parallax matters more than many shooters realise. Most centrefire scopes ship with a fixed parallax set at either 100 or 150 yards, which is fine for zeroing but can introduce apparent point-of-impact shifts if your eye moves off the optical axis at other distances. A side-focus or adjustable-objective parallax knob lets you eliminate parallax error at any range, which is especially useful if you also shoot at 50 or 200 yards. For dedicated 100-yard zeroing and general stalking, a fixed-parallax scope set at 100 yards is perfectly adequate.

Consider whether you need a first focal plane (FFP) or second focal plane (SFP) reticle. FFP reticles scale with magnification, so your mil-dot or Christmas-tree holdover marks are accurate at every power setting — a real advantage if you use the reticle to estimate drop or wind without touching turrets. SFP reticles stay the same visual size regardless of zoom, which many UK stalkers prefer for a cleaner sight picture at low magnification, but the subtension values are only correct at one specific magnification (usually the highest). For zeroing itself either plane works identically; the choice affects how you use the scope afterwards.