Air Rifle Accuracy
How to Test Five Pellets on One Target Sheet
Most pellet tests fall apart not because the shooting was bad but because the bookkeeping was. Five tins, five separate sessions, five different afternoons of wind — and a result that tells you more about the weather than the pellet. Putting all five candidates on one sheet, in one sitting, fixes most of that for free.
The problem with testing one pellet at a time
A pellet test is a comparison, and a comparison is only as good as the things you held constant. Shoot pellet A on Tuesday evening and pellet B on Saturday morning and you have changed the temperature, the wind, the light, your fill pressure, and — the big one — how well you happened to be shooting that day. Any of those can swamp the difference between two decent pellets.
The differences you are hunting for are small. Two good pellets in a good barrel are often separated by only a few millimetres — less than the difference a mediocre day behind the rifle makes on its own. So the more of the test you can compress into a single session, the more of the result belongs to the pellet.
The principle: change one thing at a time. In a pellet test the one thing is the pellet. Everything else — distance, rest, rifle, fill band, you, the hour — should be as close to identical as you can make it.
One sheet, five aim points
The practical answer is a target with several aim points spread far enough apart that shooting one doesn't destroy another. Five is a sensible number: enough to cover a shortlist, few enough to finish in one fill and one weather window.
One sheet = five strings = five pellet types, without shooting out a single aim point.
Keep the aim points well separated — roughly 100 mm at 25 yards, and nearer 150 mm if you are testing at 50 — so a bad group around one bull can't be confused with the group around its neighbour. Fix which bull is which before you shoot — the layout gives you A to E, so the only thing you have to record is which pellet goes on which letter, at the moment you start that string rather than an hour later.
You do not need a special target for this. Any card with a printed millimetre grid, a ruler, or a scale bar works, and so does a plain sheet with five stick-on dots if you are measuring by hand — though a printed grid or a ruler laid on the card is what lets a phone scale the photo for you. What matters is that each bull's point of aim is a known, fixed location.
Record the pairing as you go, not from memory. The single most common way a pellet test goes to waste is finishing five groups and no longer being certain which tin went where. Log the pellet against the bull at the start of each string — this is exactly the job the Pellet App session log does, and it is why the tin, the weight and the lot end up attached to the group instead of scribbled on a card you will throw away.
Rules that keep the test honest
Five bulls on one sheet removes the day-to-day variables. These are the ones it doesn't remove, and what to do about each.
Shoot one pellet at a time, with settling shots between
Finish each pellet completely before you start the next. It is tempting to cycle between bulls to spread the afternoon's conditions evenly across all five — but that is the wrong trade in an air rifle barrel.
Pellets are lead, but not all lead behaves the same: some are near-pure and soft, others are hardened with a little antimony, and some come waxed or lubricated while others are dry. Add differences in head size and skirt, and each pellet leaves its own residue in the bore. A barrel needs a few shots to settle after a change of pellet, and until it has, the shots are telling you about the previous pellet as much as the current one. Cycling shot by shot guarantees that every shot in the test is fired through a bore fouled by something else. You would be measuring the transition, not the pellet.
So: settling shots after every pellet change, then the group. Fire them into a backer, a spare card or the bank — anywhere off the scoring sheet. How many the barrel needs varies; five is a common starting point and some rifles want more. If you have never checked, shoot ten settling shots and watch where the group tightens up. That is your number, and it is worth knowing once rather than guessing every time.
Handle session drift with a repeat group, not rotation
Shooting in blocks does leave a real problem: the wind, the fill pressure and your own shooting all move across a session, and whatever you shoot last carries that drift. The answer is not to interleave the pellets — it is to measure the drift and see whether it mattered.
Shoot pellet A first. Shoot B, C, D and E. Then shoot A again, on a second sheet or a spare bull. If the two A groups are close, conditions held and the ranking is trustworthy. If the second A group is much worse, something drifted, and the pellets you shot late in the session were judged unfairly — bin the session and shoot it again on a better day. That single control group tells you more than rotation ever could, and it costs five pellets. It only works if both A groups were measured the same way, which is the quiet argument for measuring from a photograph rather than by hand.
Randomising which pellet goes first from session to session is worth doing too. Randomise the order of the pellets, never the order of the shots.
Stay inside one fill band
On a PCP, velocity is only flat across part of the fill. Run the whole test inside that band. On a regulated PCP you can top up between rounds. On an unregulated one, don't — a refill puts you back at the top of the curve rather than in the flat part of it, so work out how many shots your sweet spot gives you and size the test to fit. On a springer this section doesn't apply at all. If you don't know where your rifle's flat band is, that is a chronograph question worth answering before a pellet test, not during one.
Don't re-zero mid-test
Different pellets will land in different places relative to your point of aim — that is expected and it is not what you are measuring. You are measuring group size, not where the group sits. Resist adjusting the scope between strings; you'll only make the sheet harder to read. Sort the zero out afterwards, with the pellet you chose. Our zeroing guide covers that step.
Shoot from a rest, and use the same one
A bipod, a bag, a bench — it doesn't much matter which, as long as it is the same for all five strings and it takes most of you out of the equation. A pellet test shot off a wobbly improvised rest measures the rest.
One exception: a spring or gas-ram rifle should not be laid directly on a hard rest. Rest your hand on the bag and the rifle on your hand, or it will throw shots no pellet can fix.
Pick a still day, or note the wind
Wind moves groups sideways and it does not do so evenly across an afternoon. Still conditions are ideal. If you can't have them, at least record what the wind was doing per round so a suspiciously wide horizontal group can be explained rather than blamed on the pellet — see reading the wind.
How many shots per bull?
Five is the practical minimum and ten is meaningfully better. Three-shot groups are close to useless for comparing pellets: three shots can fall into a tight cluster by luck often enough that the ranking you get from them is largely noise.
The arithmetic of a five-bull sheet, not counting settling shots after each pellet change:
| Shots per bull | Total shots | What you get |
|---|---|---|
| 3 | 15 | Not enough. A rough sanity check at best — don't rank pellets on it. |
| 5 | 25 | Workable. Will separate a clearly good pellet from a clearly bad one. |
| 10 | 50 | Good. Enough to trust a close result between two similar pellets. |
Better still, shoot the sheet twice. Two five-shot groups per pellet beats one ten-shot group at exposing a pellet that is inconsistent rather than merely wide, which is why the pillar guide sets two groups per pellet as the baseline. A second sheet costs you nothing but another 25 pellets.
At that margin, how you measured starts to matter as much as what you shot — worth remembering before you declare a winner on a hand-measured sheet.
If two pellets finish within a couple of millimetres of each other on a 5-shot test, you have not found a winner — you have found two candidates for a longer test. Run those two again at ten shots each and let the rest go.
What has to be captured for each bull
The result is only useful later if you can buy the same thing again. Whether you keep it in an app or a notebook, each pellet on the sheet needs:
- Brand and model — obviously.
- Weight in grains — the same model is often sold in several weights and they do not shoot alike.
- Head size — where the tin states it. 4.50 and 4.52 of the same pellet can group very differently in the same barrel.
- Lot or batch number — the one everybody skips and the one that explains why the tin you bought a year later shoots worse.
- Distance and conditions — the number is meaningless without the distance it was shot at.
That is five fields times five pellets, at the range, in the cold, between strings — which is precisely why it is the part people skip and the reason a sheet from last season usually can't be acted on. It is also the part an app is simply better at than a cold pair of hands. Terms you're unsure of are in the glossary.
Reading the sheet afterwards
Measure each group centre-to-centre: the distance between the centres of the two furthest-apart holes. If you are measuring outer edge to outer edge with a ruler, subtract one pellet head diameter to get the same figure — roughly 4.5 mm for .177 and 5.5 mm for .22. Just never compare an edge-to-edge number with a centre-to-centre one across the five. Measuring from a photograph sidesteps the problem entirely, because the method can't drift between the first group and the fifth. The group size chart has the benchmarks for what counts as good at 25, 30 and 50 yards.
Then look at the shapes, not just the sizes. A pellet that produces a fat round group is behaving differently from one that strings vertically, even if the two measure the same — the round one is usually a pellet-fit problem and the vertical one is usually a velocity problem, which means it may not be the pellet's fault at all. What your group shape is telling you goes through the patterns, and the Pellet App analysis comments on the shape and its likely cause rather than just handing back a number.
Doing this with the Pellet App
The measuring and the bookkeeping are the tedious half of this, and they're the half Pellet App is built to take over. A session holds a string per pellet, and the string carries its own pellet, distance and shot count — so the pairing between bull and tin lives with the data instead of on the card.
Photograph the sheet and the app finds the pellet holes, reports how many it detected against how many it expected, and lets you mark or refine any it missed. It takes its scale from references printed on the card itself — a ruler or a millimetre grid — so it works on commercial targets you already own. Each group comes back in millimetres and in MRAD, with a rating band.
Several groups on one sheet are handled as separate bullseyes, so a five-pellet sheet stays five results rather than one confused blob, each with its own group size.
Five candidates, one sheet, one afternoon. Pellet App handles the measuring so the numbers are consistent across all five, and keeps each string's pellet, distance and conditions attached to the result — so the test is still worth something in six months, when the card is long gone. Pellet App is in development for iOS and isn't released yet; the waitlist is how you hear first.
Join the waitlist →
Common questions
Can I test different pellets on the same target sheet?
Yes, and it is better than testing them on separate sheets on separate days. Use a target with several aim points spaced far enough apart that the groups can't overlap — around 100 mm between bulls at 25 yards, nearer 150 mm at 50 — and record which pellet is on which bull at the start of each string, in your session log rather than from memory afterwards. Testing them together is what lets you attribute the difference to the pellet rather than to the conditions.
How many pellets should I test at once?
Four or five is the sweet spot. Fewer and you may miss a good option; many more and the session gets long enough that conditions and fill pressure drift meaningfully from the first string to the last, which is the thing a one-session test exists to avoid. Shortlist on reputation for your calibre and rifle type, then test that shortlist properly.
How many shots per group for a pellet test?
Five is the workable minimum and ten is better. Three-shot groups vary too much by chance to rank pellets reliably. If two pellets come out within a couple of millimetres of each other over five shots, treat that as a tie and re-test just those two at ten shots rather than declaring a winner.
Does the order I shoot the pellets in matter?
Shoot each pellet as a complete block, never one shot at a time in rotation. Every pellet fouls the barrel differently, and the bore needs several settling shots after a change before the groups mean anything — cycling between pellets means every single shot is fired through a bore conditioned by a different pellet. Order does still matter for a different reason: conditions and fill pressure drift across a session, so whatever you shoot last is judged in different conditions from what you shot first. Deal with that by re-shooting your first pellet at the end as a control group. If the repeat matches the original, the session was stable; if it doesn't, throw the session away.
Do I need to re-zero between pellets?
No — and you shouldn't. Different pellets landing in different places is expected and isn't what the test measures. You are comparing how tightly each pellet groups, not where the group sits. Adjust the scope once, after you've picked a pellet.