.17 HMR ammo buying guide
.17 HMR is a .22 WMR necked down to a 17 grain bullet at 2,550 fps. The flat trajectory is the point; the explosive bullet performance and the backstop requirement come with it.
By TAS6 min read
.17 Hornady Magnum Rimfire is a .22 WMR case necked down to accept a .172" bullet, and it is the flattest-shooting rimfire in common use at practical varmint ranges. A 17 grain polymer-tipped bullet leaves the muzzle at about 2,550 fps from a 24" barrel and holds a trajectory close enough to flat that holdover is rarely a problem inside 150 yards. That is the entire argument for the cartridge, and the ammunition choices exist to serve it.
HMR versus HM2, and why the distinction matters
There are two .17 rimfires on the shelf and they are not variants of each other. .17 HMR is based on the .22 WMR case and runs a 17 grain bullet at roughly 2,550 fps. .17 HM2 — .17 Mach 2 — is based on the .22 LR case and runs the same weight at about 2,100 fps. HM2 is closer to a hot .22 LR; HMR is a genuinely different class of velocity. They do not interchange, and the chambers are different.
Most shooters who are comparing “.17” options mean the HMR. It is the one with the long-range trajectory, the one with the widest load menu, and the one this guide is about. If you already own an HM2 rifle and are happy with it, keep shooting it; if you are buying a rifle and ammunition together, buy the HMR and never look back. The HM2 has its place as a quiet, cheap small-game round, but it is not what anyone means when they ask for a flatter-shooting rimfire.
Ammunition availability also favours the HMR. Every major rimfire manufacturer loads it, and the shelf typically carries several 17 grain polymer tips, at least one 20 grain option, and occasionally a 25 grain load for wind. HM2 is a thinner market, usually one or two loads deep, which is fine if you have already committed to the chamber and less fine if you are still deciding.
The load menu
| Weight | Velocity | Bullet | Best at |
|---|---|---|---|
| 17 gr | 2,500–2,550 fps | Polymer tip (V-MAX style) | Varmints, flatter trajectory |
| 20 gr | 2,300–2,350 fps | Polymer tip, jacketed | Heavier varmints, some wind |
| 25 gr | 2,100–2,150 fps | Jacketed, heavier | Windier shots, slightly larger game |
The heavier bullets trade trajectory for wind tolerance. At 150 yards the 17 grain load is still shooting flatter than a .22 LR does at 75; the 20 and 25 grain loads give up a little of that edge and hold their line better when a crosswind comes up across a field. Zero for the load you shoot: the point-of-impact difference between 17 and 20 grain is routinely an inch or more at 100 yards in the same rifle.
Barrel length deserves a second mention because the velocity loss on a short barrel is proportionally worse here than on a centerfire. A carbine-length 16" barrel is a compromise that works; a 20–22" barrel is what the cartridge was designed around, and the difference shows up most past 125 yards, exactly where you bought a .17 HMR to shoot. If your rifle is a short-barrelled semi-auto for hunting from a blind, that is a fine trade — just know you are making it.
What the bullets do on impact
The polymer-tipped .17 HMR bullets are designed to fragment on impact rather than to expand and hold together. That is exactly right for varmints — prairie dogs, groundhogs, foxes, coyotes at sensible rimfire ranges — and it is exactly wrong for anything you intend to eat that is larger than a rabbit, or for any defensive use. The cartridge produces dramatic results on light animals because the bullet is moving fast and coming apart; that is a terminal-performance characteristic, not a quality judgment.
Barrel length, twist, and what to practise with
A 20–22" barrel is the practical sweet spot for a .17 HMR rifle; a 16" barrel is usable and loses a noticeable amount of the velocity that makes the cartridge worth owning. Twist rate in factory rifles is fast enough for the 17 and 20 grain bullets, and most will also stabilise the 25 grain. As with every rimfire, buy a box of each weight you are considering and let the rifle tell you which one it prefers.
The cheapest in-stock price on the .17 HMR page is currently $0.28 a round, which is about the same as .22 WMR and roughly twice .22 LR practice ammunition. That is a sensible trade for a varmint cartridge; it is not a sensible trade for volume practice, which belongs on a .22 LR. For the rimfire that sits next to this one on the shelf, see the .22 WMR guide.
A sensible first order
- One box of 17 grain polymer tip — the default varmint load, and the one that shows what the cartridge was designed to do.
- One box of 20 grain to compare trajectory and wind behaviour in your own rifle at the ranges you actually shoot.
- 100 rounds of whichever won for practice and zero confirmation before season.
- A magnified optic with a known reticle, if you do not already have one. A cartridge this flat rewards a scope you trust; holdovers only work if the reticle matches the trajectory you are actually shooting.
Sorted by bullet weight and intended use, the shelf is on the .17 HMR caliber page. If you are also shopping a shotgun for the same safe, the 12 gauge guide covers a completely different kind of versatility, and the flat-shooting arithmetic behind this cartridge’s trajectory is in understanding grain weight.
Shop this caliber
Live prices from the warehouses that have it on a shelf right now.
