Rifle scopes improve precision and target ID. This guide covers the basics—magnification, objective size, reticles—and how to size your rings for a clean, repeatable fit.
How to choose a scope
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Magnification: LPVO (1–6×/8×) for close to mid-range; 3–9× for all-round hunting; 4–16× or 6–24× for longer distances.
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Objective size: 24–56 mm; bigger objectives gather more light but need taller rings.
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Reticle & turrets: simple duplex for speed, or MRAD/MOA hash for dialing/holds; pick SFP or FFP to suit your use.
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Parallax & focus: side focus (e.g., 10 m–∞) helps sharpen the image and reduce parallax error.
Ring diameter: what to measure
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Scope tube size (not the objective): common are 1" (25.4 mm), 30 mm, 34 mm. Your ring diameter must match the tube.
- Check the scope’s spec sheet for tube diameter; don’t guess from the objective bell.
Ring height: how to calculate
- Find the objective outer diameter (OD) (bell outside, not just “50 mm” lens). Many brands list this in specs.
- Use a simple rule: required centerline height ≥ (objective OD ÷ 2) + desired clearance (≈2–4 mm).
- Convert to the maker’s height format. Some list base-to-center; others list base-to-bottom of tube (add tube radius).
- Account for caps & sunshades and verify bolt-handle and barrel clearance.
Mounting base: Picatinny vs dovetail
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Picatinny rings: widest choice and QD options; requires a Picatinny rail.
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Dovetail rings: clamp to factory 11 mm/16 mm cuts; lower and lighter but fewer models and less fore/aft adjustment.
Setup tips
- Degrease screws/mating faces; use Loctite threadlocker as recommended.
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Torque to spec for bases and caps; level the reticle and set eye relief at full magnification.
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Witness-mark screws and confirm zero after the first range session.