Blog
Ballistics, optics, firearms and ammunition. Guides and tests written in our own words — not copied from manufacturer brochures.
Shot placement heatmaps — what they can and cannot tell you
The shot density map in pointMoA: how it is built, what the colour really means, why two maps are not comparable, and how many hits it takes before the map shows a pattern rather than the holes themselves.
How to Measure Shooting Groups: Extreme Spread, Mean Radius and MOA
Centre-to-centre measurement step by step, the real difference between extreme spread and mean radius, and how many shots a group actually needs before the number means anything.
How to Calculate Group Size in MOA: Formula, Examples and Pitfalls
Converting a measured group to MOA takes one division. The formula, a worked example at an awkward distance, and how much that number is actually worth — with the error budget computed.
Ballistic Calculator: How It Works and What Data It Needs
What a ballistic calculator computes, which inputs it really needs, and which one wrecks the answer hardest. With a computed ranking of every input and a procedure for checking the table on the range.
Bullet Drop Explained: What Affects It and How to Calculate It
The school formula ½gt² is both correct and misleading. Four different numbers all called drop, why a zero does not mean no drop, and what the drop column in a ballistic table actually measures.
P50 and P90 in shooting — what the dispersion ellipses tell you
In pointMoA, P50 and P90 are ellipses fitted to your hits — not radii and not CEP. Where they come from, why P90 is always 1.82 times larger, and how many hits it takes before the shape of the ellipse means anything.
Scope Parallax Explained: What It Is and How to Adjust It
Parallax error depends only on the objective diameter and on how far the setting misses the distance. The formula, worked examples, the eye-movement test, and why a sharp picture does not prove parallax is gone.
What Are POA and POI? Point of Aim vs Point of Impact
POA is where you aimed, POI is where the bullet went. Behind those two abbreviations sit three different points, and confusing them costs clicks dialled the wrong way.
Wind Drift Explained: Corrections in MOA and MRAD
Why wind moves a bullet further than instinct suggests, how to read direction off the clock face, and where the correction comes from. With a computed wind clock and a formula that matches the calculator to 0.005%.
Astigmatism and red dot sights — why the dot falls apart
The dot in your red dot looks like a star, a comet or several dots at once. Where that comes from, how to tell whether the problem sits in your eye or in the sight, and what actually helps: brightness, dot colour, corrective lenses, prism sights and holographic sights.
MOA and MRAD — what they are and how to convert them to centimetres
MOA and MRAD are units of angle, not distance. What a minute of angle and a milliradian come to in centimetres at every range, how to convert one into the other, and how far a single turret click really moves the shot.
Zeroing a rifle — the complete guide
What zeroing actually is, how to choose the distance, how many shots a trustworthy correction takes and how to turn it into clicks. With zeroing on a range shorter than your target distance, the pointMoA targets and the ballistic calculator.