Caliber Guide
Best airgun caliber for small game: .22 vs .25, answered with real numbers
By James · Updated July 24, 2026 · Editorial policy
Field protocol: every load gets a 10-shot chronograph string (average velocity, extreme spread, energy) before it's trusted on game. Holdovers are confirmed at real distances, then re-confirmed in field conditions. Shots are recorded through the scope cam, and claims on this page link to footage where it exists. Full methodology & editorial policy →
The energy math (this is the whole argument)
Caliber debates get religious. Energy numbers don't. Foot-pounds of energy is weight × velocity² ÷ 450,436, and here's what common hunting loads actually produce at the muzzle:
| Caliber & load | Weight | Velocity | Muzzle energy |
|---|---|---|---|
| .177 — 8.44gr domed | 8.44gr | 900 FPS | ≈15 FPE |
| .22 — 18.1gr heavy domed | 18.1gr | 880 FPS | ≈31 FPE |
| .25 — 33.95gr heavy domed | 33.95gr | 880 FPS | ≈58 FPE |
| Slug — 40.1gr (my hunting load) | 40.1gr | chrono-verified per rifle | run yours in the calculator |
Two honest conclusions from that table. First: a .22 at normal PCP power already carries roughly triple the energy a rabbit or squirrel needs at typical airgun ranges — more caliber isn't buying you a cleaner kill, shot placement is. Second: the .25's extra energy is real, but you pay for it with a loopier trajectory at equal power, roughly double the pellet cost, and a rifle that must be genuinely powerful to push those weights. That's why .25 belongs on high-power PCPs or it belongs on the shelf.
Don't trust the box velocity either. Advertised numbers come from featherweight alloy pellets nobody hunts with. Chronograph your actual hunting load — it's the difference between knowing your energy and guessing it. (That's the entire reason a chronograph lives in my range bag.)
Is .22 or .25 better for rabbits specifically?
.22, for almost everyone. Rabbits are thin-skinned with light bone; they do not require .25 energy to be taken cleanly. What kills rabbits reliably is hitting a golf-ball-sized brain zone at unknown ranges — and that's a trajectory problem, which the faster, flatter .22 makes easier. A .25 body shot also wrecks meat you presumably wanted.
Pick .25 for rabbits only when: your rifle is a high-power PCP that keeps .25 pellets fast, you're stretching past 50 yards, or you hunt in wind where the heavier pellet's drift resistance genuinely matters. Those are real advantages — they're just advantages most rabbit hunters never use.
Slugs vs pellets — from someone who hunts with slugs
My Impact M4 shoots 40.1gr ACE FRAG slugs on hunts, so understand I'm arguing against my own setup here: most small-game hunters should shoot diabolo pellets.
Pellets win when
- Shots are inside ~50 yards (nearly all small game)
- You hunt backyards or semi-suburban ground — pellets shed velocity fast, so misses are safer
- Your rifle is a springer, gas-ram, or standard PCP — almost every barrel shoots pellets well
- You care about cost per shot
Slugs win when
- You're shooting 50–100+ yards — higher ballistic coefficient keeps energy and fights wind
- Your PCP has the power and a slug-friendly barrel, and you've proven the combo groups
- You accept more penetration and ricochet risk and choose ground accordingly
The rule I actually follow: accuracy beats projectile fashion. If your rifle groups pellets better, hunt with pellets — a perfectly placed pellet beats a slightly-off slug every single time. I shoot slugs because my specific barrel/load combo proved itself over the chrono and on paper first, not because slugs are cool.
Beginner: pellet gun or PCP?
Short version — the full breakdown is in Pellet Gun vs PCP: under about $300, buy a quality gas-ram break-barrel in .22 and learn to shoot it. With $500+ available, start with an entry-level PCP and a hand pump; near-zero recoil makes a beginner accurate in an afternoon instead of a season. The break-barrel path is cheaper, the PCP path is easier — pick which problem you'd rather have.
Quietest backyard pest setup
Three noise sources, three fixes: (1) sonic crack — keep pellets subsonic, under ~950 FPS, with heavy projectiles; (2) muzzle blast — a fully shrouded barrel or a quality airgun moderator where legal; (3) mechanical noise — PCPs have essentially none, springers slap a steel piston next to your ear. Put together: a moderated, shrouded .22 PCP shooting heavy pellets subsonic is quieter than a hand clap. And check your city's discharge ordinance before any of this matters — the guide to backyard pest control covers legality and safe backstops.
Bottom line
One rifle for most people: a .22 PCP shooting quality domed pellets. Simplest budget path: a .22 gas-ram break-barrel. Max authority at range: .25 on a high-power PCP, accepting cost and rainbow trajectory. Quiet backyard work: shrouded .22 PCP, heavy subsonic pellets, safe backstop. Then stop shopping and go practice — placement kills, calibers don't.
Gear that matches this guide
FAQ
What is the best airgun caliber for small game?
.22 is the best all-around airgun caliber for small game like rabbits and squirrels. It balances energy, trajectory, pellet cost, and availability better than .177 or .25. Aim to deliver at least 9–12 FPE at the animal with a headshot for a clean, humane kill.
Is .22 or .25 better for hunting rabbits?
.22 is better for most rabbit hunters. Rabbits are thin-skinned and don't need .25-level energy; a .22 shoots flatter, costs less per shot, and makes range estimation easier. Choose .25 only if you run a high-power PCP and want extra energy for longer shots or windy conditions.
Are slugs better than pellets for airgun hunting?
Not by default. Diabolo pellets are more accurate in most rifles inside 50 yards, cheaper, and safer in backyards because they shed velocity fast. Slugs win past 50 yards from high-power PCPs with slug-friendly barrels — they carry energy and buck wind far better, but over-penetrate and ricochet more.
Should a beginner buy a pellet gun or a PCP?
Under about $300, buy a quality gas-ram break-barrel and learn on it. If you can spend $500+ including a fill source, start with an entry-level PCP — near-zero recoil makes accuracy dramatically easier. PCPs are better shooters; break-barrels are better budgets.
What is the quietest airgun setup for backyard pest control?
A moderated .22 PCP with a shrouded barrel, shooting heavy pellets below about 950 FPS. Subsonic velocity avoids the sonic crack, the shroud/moderator tames muzzle blast, and a PCP has no spring-piston clatter. Always confirm local discharge laws first.