Rimfire vs. Varmint Centerfire

You glass a groundhog feeding in the middle of the pasture — a solid 220 yards out. You have your .22 LR. The math does not work in your favor: by the time that 40-grain bullet reaches 200 yards, it has dropped more than 24 inches and barely holds 70 foot-pounds of energy. That chuck is going to feel a tickle, flinch, and disappear into his hole. Cartridge choice is the first decision a varmint hunter makes — and the wrong one means clean misses, wounded animals, or long crawls that never close the gap.

Quick recall

Quick recall from The Piedmont Groundhog — a groundhog in open pasture is typically how far when you first spot it?

Quick recall from The Piedmont Groundhog — a groundhog in open pasture is typically how far when you first spot it?

Under 50 yards — they stay near cover 50–150 yards in most field situations 100–300 yards when feeding in open fields

Check answer

Two families of cartridge

All four common groundhog cartridges fire a .224-inch bullet, so the projectile diameter is the same. What separates them is how fast that bullet gets there and how much energy it carries along the way.

Rimfires — .22 LR and .22 WMR — ignite when the firing pin crushes the rim of the case. They are economical, modestly quiet compared to centerfires, and built into a huge selection of inexpensive, lightweight rifles. The tradeoff is a relatively slow bullet that sheds energy fast and curves downward noticeably beyond 75–100 yards.

Centerfires — .223 Remington and .22-250 Remington — fire when a primer in the center of the case ignites a larger powder charge. The result is roughly three to four times the muzzle velocity of a .22 LR and a trajectory that stays flat enough to reach 200–300 yards reliably. They are louder (hearing protection required, every shot), produce more recoil, and ammunition costs more.

The why Why rimfire cases can't simply hold more powder

A rimfire’s ignition system is built into the folded rim of the brass case itself, which limits how thick and strong the case walls can be. A centerfire case uses a separate, robust primer pocket and thicker walls, so it can safely contain the higher pressures a faster powder charge generates. This is fundamentally why the rimfire ceiling for a .22-caliber bullet is around 2,200 fps, while the .22-250 pushes past 3,800 fps.

The rimfire pair: .22 LR and .22 WMR

The .22 Long Rifle is the most common cartridge in the world. A 40-grain bullet leaves the muzzle around 1,080 fps and carries about 137 foot-pounds of energy. By 100 yards it has dropped roughly 5–6 inches (when zeroed at 50 yards) and retains under 100 foot-pounds. For a groundhog, that is marginal energy at best — and it assumes a precise hit at a range where the arc is already bending hard. Keep .22 LR for burrow setups where the distance is under 75 yards and you can guarantee a steady rest.

The .22 Winchester Magnum Rimfire (.22 WMR) launches the same diameter bullet at 1,875–2,200 fps — nearly double the .22 LR — and holds around 314 foot-pounds at the muzzle. At 125 yards a .22 WMR carries roughly the same energy a .22 LR has at the muzzle. That matters. Practical groundhog range for the .22 WMR stretches to 125–150 yards with care, which covers a lot of Piedmont field-edge burrows. It is still a rimfire, meaning the same bolt or semi-auto platform — just more reach.

Edge case Noise matters on farms

Centerfires are genuinely loud — a .22-250 is around 156–160 decibels at the muzzle, well above the threshold that causes instant hearing damage. A .22 LR is noticeably quieter. On a dairy farm where you are shooting fifty rounds and livestock are nearby, noise and neighbor relations are real considerations. Rimfires also produce less muzzle blast that might spook remaining chucks. Neither is a reason to use the wrong tool at the wrong range — but it is a legitimate trade-off when the ranges are honest rimfire distances. Always wear hearing protection regardless of caliber.

The centerfire pair: .223 Rem and .22-250 Rem

The .223 Remington (also sold as 5.56×45mm NATO in military-specification loads) fires a .224-inch bullet — typically 40–55 grains for varmint work — at 3,200–3,400 fps. Zeroed at 200 yards, a 50-grain .223 drops only about 4–5 inches at 300 yards. Ammunition is widely available and is among the least expensive centerfire options. The .223 is the entry point for open-field varmint work and handles 90% of Piedmont groundhog shots comfortably.

The .22-250 Remington adds roughly 200–400 fps over a comparable .223 load — pushing a 40–50 grain bullet at 3,800–4,000 fps. The result is a flatter trajectory (about an inch less drop at 300 yards for comparable bullet weights) and less wind drift, which is the real advantage on a breezy day with a 4-inch target. The trade-off is louder muzzle blast, heavier recoil than the .223 (though still modest), faster barrel heating on a long shooting session, and slightly higher ammo cost. For most Piedmont field distances — 150 to 250 yards — the .223 and .22-250 are nearly equivalent in practice. The .22-250’s edge shows at 300+ yards or in significant wind.

Effective range: the full picture

Trajectory is only one part of effective range. A cartridge’s practical limit is the distance at which all four of these stay true:

1. Enough retained energy to dispatch quickly and ethically
2. Trajectory flat enough that your holdover is known and confident at that distance
3. Wind drift manageable for your skill level
4. You can hold a steady enough position to actually land the shot

A .22-250 can carry enough energy to 400 yards — but that doesn’t mean a beginner shooting offhand in a gusty field should shoot a groundhog at 400 yards. The ethical effective range is the distance at which you, with your rifle and your rest setup, reliably put the first shot in the vitals. Start closer than you think you need to, then extend as your skill and confidence build.

The cartridge-to-distance match-up (visual anchor)

.22 LR — under 75 yd .22 WMR — to 150 yd .223 Rem — to ~300 yd .22-250 Rem — to 350 yd+

Make the call — match cartridge to situation

Knowledge check

A groundhog is sitting at a burrow entrance 60 yards from the field edge where you are set up with a solid bipod rest. Which cartridge is a reasonable choice here?

A groundhog is sitting at a burrow entrance 60 yards from the field edge where you are set up with a solid bipod rest. Which cartridge is a reasonable choice here?

.22 LR — close range, low noise, low cost .22 WMR — better energy margin for a clean kill .22-250 — flattest trajectory, best choice regardless

Check answer

Knowledge check

You spot a groundhog feeding in the open pasture. Your laser rangefinder reads 240 yards. A crosswind is gusting. Which cartridge family is clearly the better choice?

You spot a groundhog feeding in the open pasture. Your laser rangefinder reads 240 yards. A crosswind is gusting. Which cartridge family is clearly the better choice?

A centerfire — .223 or .22-250 .22 WMR — it reaches 150 yards, so 240 yards is close enough .22 LR — if you aim high to compensate for drop

Check answer

Take it to the woods (and the hayfield)

Before your next groundhog outing, do this scouting session from a distance before picking up the rifle.

Pre-hunt cartridge decision checklist

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Reset

• Scout the field: estimate the typical distance from your planned position to where chucks feed or sit at burrows.
• Match cartridge to that distance: rimfire for under 100 yards, centerfire for over 150 yards.
• ⚠ Safety Pack hearing protection if bringing any centerfire — earplugs or earmuffs, not optional.
• Identify your rest setup: bipod, pack, or shooting sticks determine how far YOUR effective range actually extends.
• Confirm hunting license is valid for the land you are hunting (verify current SCDNR regulations at dnr.sc.gov).

Sources

• Ammunition comparison — .22 LR vs. .22 WMR ballistics: https://www.ammunitiontogo.com/lodge/22-wmr-vs-22lr/
• .22 WMR ballistics chart: https://www.ammunitiontogo.com/lodge/22-wmr-ballistics/
• .22-250 vs. .223 comparison: https://www.sportsmans.com/22-250-vs-223-cartridge
• .22-250 ballistics and varmint guide: https://gunvera.com/articles/22-250-remington-complete-guide
• Choosing a varmint rifle: https://greatdaysoutdoors.com/varmint-rifle/
• SCDNR hunting licenses and regulations (verify current rules): https://dnr.sc.gov/regulations.html