Is the .17HMR the best hunting rimfire ever made?

The .17HMR is a wonderful cartridge for pests and small game. It is an inherently accurate rimfire round that shoots flat to 150yds. Its tiny projectiles have explosive terminal ballistics that kill small animals like a lightning bolt. It has redefined small game hunting and close range varminting since being developed by Hornady (HMR stands for Hornady Magnum Rimfire) in 2002. The .17HMR is based on the .22 Magnum rimfire case, necked down to take 0.172″ (4.40mm) diameter projectiles. It is loaded with a full case of fine ball powder, probably a slightly compressed load even, that gets those 0.172″ projectiles fairly zinging out of the barrel.

When it first came out, I was impressed by the claimed ballistics and eagerly awaited first-hand reports from acquaintances who were quick to buy the new rifles. The feedback was positive, so I too quickly acquired a CZ in .17HMR. It immediately demonstrated that the glowing reports were not exaggerated. Rabbits, hares, foxes and cats died instantly when hit by that tiny little projectile. I’ve walloped those critters with calibres such as the 7mm Rem Mag and .257 Weatherby Magnum and, while those calibres blow ‘em to smithereens, they do not kill them any faster.

Most times, the .17HMR projectile blows up in the body of small game and does not exit. On a miss, the projectile vaporises on grass or the earth and this makes it a particularly safe calibre for shooting in and around farm infrastructure. Additionally, the .17HMR has a rimfire level noise, which makes it a good choice for shooting on farms that neighbour urban sprawl.

The .17HMR fires projectiles of 15.5gr, 17gr and 20gr. Velocities range through 2650, 2550 to 2375fps respectively for those bullet weights. The lighter projectiles are polymer-tipped while the 20gr is a jacketed hollow-point. The designers have done a great job in matching the jacket thickness and lead core softness to ensure explosive expansion, even out to the limit of the calibre’s sensible range.

I sight rimfires to be no more than an inch (25mm) above the line of sight in their trajectory. For the 20gr .17HMR, that gives a point of impact at 100yds of +0.9″ (20mm) and a zero at 125yds. Out at the 150yds/m mark the projectile is dropping and 2″ (50mm) below the line of sight. So, the little rimfire is flat-shooting out to 150yds distance. On a calm day, you can take advantage of that and pull off spectacular shots. Keep in mind that the little projectile is much more prone to wind drift than are heavier centrefire bullets and any sort of breeze will push it about, significantly.

I’ve owned several .17HMR rifles over the past 20 years. I was always happy with their accuracy and performance, and feel that accuracy has improved since its introduction. I presume refinements in the manufacturing process and improvements in rifle manufacture have contributed to deliver that. The narrow bore of the .172 barrel offers a few engineering challenges that are not present in making larger calibres. Additionally, the small rimfire cartridges also pose a number of challenges to consistent manufacture that are not an issue in centrefire calibres. That, and the .17’s susceptibility to wind, mean that consistent tight groups can sometimes be difficult to achieve. Looking over my records, I can say that 1 MOA is an overall benchmark accuracy for the .17HMR, across the various brands of ammo and variable weather conditions. So, on a good day you can aspire to sub-MOA and on a not so good day a bit more than MOA.

One aspect I note is once you find the particular ammo your rifle prefers, it can be frustratingly common to get four-shot clover leaf groups with a fifth flier blowing the group size out. Every now and then you will be blessed with a 5-shot group of 0.3 MOA or similar. The Hornady 20gr XTP is like that in my current rifle. Overall, its average group size is 1 MOA, which is a smidge better than the other ammo offerings. However, many of those groups are four shots under 0.5 MOA with the fifth a flier. The other ammo averages about the same but with a more consistent random scattering of shots in each group. For me that made the 20gr XTP an obvious choice because 4 out of 5 shots are well under MOA and the odd flier is no worse than you would expect from the other types. I shoot my targets at 50m and draw a circle where I want the rifle to put its groups. I use a 5c piece for the circle, placed 20mm above point of aim at 50m, which represents 0.9 MOA, a handy immediate reference when I am shooting on the day.

The .17HMR is my go-to gun for rimfire hunting. The .22LR is now for target practice and plinking. The .17HMR offers much better accuracy, range and authority for taking game. Like all new calibres, when they first come out there are a lot of exaggerated claims that soon prove to be incorrect. The .17HMR was touted as the new wonder calibre for creatures large and small. My very firm impression is that the .17HMR is small game only, restricted to rabbits, hares, cats, foxes and pest bird species, but nothing larger. I know that in the USA a lot of folks swear by the .17HMR for shooting coyotes. I would only be tempted to take a shot at a wild dog if the range was close and I had a steady shot. I suspect that our wild dogs are much more robust than coyotes. The capabilities of the .17HMR are astounding, but it is a calibre that needs to be kept within its recognised limits.