The best overall barrel length for a .17 HMR (Hornady Magnum Rimfire) is 18 to 20 inches because rimfire powders burn completely within a short distance, allowing the lightweight 17-grain bullet to reach its peak velocity without adding unnecessary weight.
This length provides an ideal balance of flat trajectory, precision accuracy, and a long sight radius for field use.
Because the .17 HMR is a high-velocity rimfire cartridge, subsonic performance is non-existent; all factory loads leave the muzzle travelling at supersonic speeds (around 2,550 fps).
While a 16-inch barrel makes for an ultra-handy pack rifle, stretching to 20 or 22 inches helps tame muzzle report and balances nicely off a benchrest.
Ultimately, the best barrel length depends on whether you prefer a nimble 16-inch varmint stalker or a steady 20-inch precision target rifle.
Best Barrel Length For 17 HMR
| Barrel Length | Typical Velocity (17gr V-MAX) | Muzzle Energy (17gr) | Supersonic Performance | Subsonic Performance | Best Use | Overall Rating |
| 16 inches | ~2,475 fps | ~231 ft-lbs | Excellent | N/A | Backpack / Light Stalking | 4/5 |
| 18 inches | ~2,525 fps | ~240 ft-lbs | Excellent | N/A | General Varmint Hunting | 5/5 |
| 20 inches | ~2,550 fps | ~245 ft-lbs | Maximum | N/A | Benchrest / Precision | 5/5 |
| 22 inches | ~2,565 fps | ~248 ft-lbs | Maximum | N/A | Target Shooting | 4/5 |
| 24 inches | ~2,575 fps | ~250 ft-lbs | Maximum | N/A | Vintage / Heavy Target | 3/5 |
The table above illustrates a fundamental law of rimfire ballistics: powder burnout occurs very quickly. Unlike centerfire cartridges that require long barrels to consume massive powder charges, the tiny .17 HMR case burns all of its propellant within the first 14 to 16 inches of the bore. Pushing beyond 20 inches yields almost zero velocity gain (roughly 5 to 10 fps per inch), making extra barrel length purely a tool for adjusting balance, sight radius, and weight.
Comprehensive 17 HMR Barrel Analysis
What Is The Best Barrel Length For 17 HMR?
An 18 to 20-inch barrel is widely regarded as the best overall length for a .17 HMR rifle. It captures 99% of the cartridge’s velocity potential, ensuring that 17-grain and 20-grain polymer-tip bullets achieve the fragmentation speed necessary for instant ethical kills on small varmints out to 150+ yards, all while keeping the rifle light and nimble.
17 HMR 16 Inch Barrel
A 16-inch barrel is popular for lightweight, highly portable tactical or threaded-barrel carbines. It sacrifices only about 75 fps compared to a 22-inch test barrel. This minor loss in velocity has virtually zero impact on terminal ballistics, making a 16-inch .17 HMR an exceptional choice for a truck gun or a mobile stalker.
17 HMR 18 Inch Barrel
The 18-inch barrel is a fantastic middle ground found on many popular bolt-action rimfires. It provides a slightly longer sight radius for iron sights and balances well whether shooting offhand or from shooting sticks. It allows standard Hornady V-MAX loads to cruise right around 2,525 fps.
17 HMR 20 Inch Barrel
A 20-inch barrel is the sweet spot for target shooters and precision rimfire enthusiasts. The added forward weight helps steady crosshairs during offhand or positional shots, and the longer barrel profile helps dampen barrel harmonics, which heavily contributes to the pin-point group sizes the .17 HMR is famous for.
17 HMR 22 To 24 Inch Barrel
Longer 22 and 24-inch barrels are frequently found on traditional heavy-barreled target rifles. While they reach the absolute peak velocity ceiling of roughly 2,575 fps, the velocity increase is negligible. These longer tubes are chosen primarily for their weight and stability on a shooting bench rather than any ballistic necessity.
Best 17 HMR Barrel Length For Supersonic Ammo
Because every single commercial .17 HMR cartridge is supersonic, any standard barrel length from 16 to 24 inches excels here. An 18 to 20-inch barrel is ideal because it ensures complete powder combustion while retaining the high-velocity shock wave needed for explosive varmint expansion.
Best 17 HMR Barrel Length For Subsonic Ammo
There is no effective barrel length for subsonic .17 HMR ammunition because subsonic .17 HMR does not commercially exist. The cartridge was engineered specifically to push tiny bullets at hyper-velocity (around 2,550 fps). Attempting to load .17 HMR to subsonic speeds is dangerous and impractical; shooters looking for a quiet rimfire platform almost universally select .22 LR instead.
Best 17 HMR Barrel Length For Hunting
The best hunting barrel length is 18 to 20 inches. Hunting small game like prairie dogs, squirrels, and rock chucks requires laser-like accuracy at distance. An 18 to 20-inch barrel offers the ideal blend of rigidity and weight to deliver consistent sub-MOA accuracy in the field.
Best 17 HMR Barrel Length For Suppressed Shooting
The best barrel length for a suppressed .17 HMR is 16 to 18 inches. Rimfire suppressors add very little weight, but a long 22-inch barrel combined with a 6-inch can makes the rifle uncomfortably long. A 16-inch threaded barrel keeps the overall system compact and easy to maneuver around farm buildings or brush.
17 HMR Velocity By Barrel Length
Chronograph data demonstrates how tightly clustered rimfire velocities are across different barrel lengths:
- Ammunition: Hornady V-MAX
- Bullet Weight: 17 grain (Supersonic)
- Barrel Length: 16 inches
- Muzzle Velocity: ~2,475 fps
- Muzzle Energy: ~231 ft-lbs
- Source: Independent Chronograph Data / Ballistics by the Inch
- Ammunition: Hornady V-MAX
- Bullet Weight: 17 grain (Supersonic)
- Barrel Length: 18 inches
- Muzzle Velocity: ~2,525 fps
- Muzzle Energy: ~240 ft-lbs
- Source: Manufacturer Reference Specs
- Ammunition: Hornady V-MAX
- Bullet Weight: 17 grain (Supersonic)
- Barrel Length: 20 inches
- Muzzle Velocity: ~2,550 fps
- Muzzle Energy: ~245 ft-lbs
- Source: Hornady Factory Specs
- Ammunition: Hornady V-MAX
- Bullet Weight: 17 grain (Supersonic)
- Barrel Length: 24 inches
- Muzzle Velocity: ~2,575 fps
- Muzzle Energy: ~250 ft-lbs
- Source: Long-Range Rimfire Testing
Use Case Comparison
| Use Case | Best Barrel Length | Why |
| General .17 HMR Use | 18 to 20 inches | Provides the best all-around balance, accuracy, and velocity. |
| Supersonic | 18 to 22 inches | Fully utilizes all available propellant for peak terminal performance. |
| Subsonic | N/A | Subsonic ammunition is not commercially manufactured for this caliber. |
| Suppressed | 16 to 18 inches | Keeps the rifle short and handy when a rimfire silencer is attached. |
| Hunting | 18 to 20 inches | Delivers pinpoint accuracy and maximum flat-trajectory performance. |
| Compact Setup | 16 inches | Maximizes portability for packing into remote areas. |
| Maximum Velocity | 22 to 24 inches | Squeezes out the absolute highest theoretical fps. |
Barrel Length vs Velocity
The relationship between barrel length and velocity in the .17 HMR is exceptionally flat. Because the case contains a very small charge of fast-burning pistol-grade powder, the bullet reaches its maximum speed quickly. Once the bullet travels past the 16 or 18-inch mark, friction begins to counteract the expanding gas pressure. Consequently, gaining additional velocity requires disproportionately more barrel length for minimal return.
Pros And Cons
Short Barrel Pros (16 Inches)
- Highly portable and fast to maneuver in tight spaces or vehicles.
- Significantly lighter weight for long days of active hunting on foot.
- Easier to manage when paired with a sound suppressor.
Short Barrel Cons (16 Inches)
- Slightly louder muzzle report due to being closer to the shooter’s ear.
- Reduced sight radius if using traditional iron sights.
Longer Barrel Pros (20 to 24 Inches)
- Heavier profile helps absorb subtle shooter movements for benchrest accuracy.
- Slightly lower muzzle blast intensity relative to the shooter.
- Maximizes the factory-advertised velocity specifications.
Longer Barrel Cons (20 to 24 Inches)
- Makes the rifle less nimble when walking through dense brush or timber.
- Adds unnecessary weight without providing meaningful ballistic gains.
What Is The Best Barrel Length For 17 HMR?
The final recommendation for the best .17 HMR barrel length is 18 to 20 inches.
- Best overall barrel length: 18 to 20 inches for optimal accuracy and handling.
- Best for supersonic: 18 to 22 inches to capture peak powder burn efficiency.
- Best for subsonic: None, as subsonic loads do not exist for this caliber.
- Best for suppressed use: 16 to 18 inches to keep the rifle compact.
- Best for hunting: 18 to 20 inches for precision varmint elimination.
- Best for maximum velocity: 24 inches, pushing 17-grain bullets to 2,575 fps.
FAQs
What is the best barrel length for 17 HMR?
The best overall barrel length for the .17 HMR is 18 to 20 inches, as it maximizes velocity and provides the rigidity required for exceptional target accuracy.
Is 16 inches enough for 17 HMR?
Yes, a 16-inch barrel is plenty long for .17 HMR, sacrificing only about 75 fps of velocity while creating an ultra-handy, lightweight rifle.
Is 18 inches the best barrel length for 17 HMR?
An 18-inch barrel is widely favored by hunters because it balances precision accuracy with a lightweight, easy-to-carry field profile.
Is 20 inches good for 17 HMR?
A 20-inch barrel is exceptional, particularly for benchrest shooting, where the added front weight helps stabilize crosshairs on small targets at long distances.
Is 24 inches too long for 17 HMR?
A 24-inch barrel is not inherently too long, but it offers diminishing returns, providing only a minor 25 fps velocity boost over a 16-inch barrel while adding unnecessary length.
What barrel length is best for subsonic 17 HMR?
There is no barrel length for subsonic .17 HMR because subsonic loads are not commercially produced for this cartridge; use .22 LR if you need quiet subsonic performance.
What barrel length is best for supersonic 17 HMR?
An 18 to 20-inch barrel is ideal for supersonic performance, ensuring the 17-grain bullet achieves its full 2,550 fps muzzle velocity.
What is the fastest 17 HMR barrel length?
A 24-inch barrel is the fastest standard length, though it only yields about 25 to 50 fps more than a standard 16-inch carbine.
Does a longer 17 HMR barrel increase velocity?
Yes, but only slightly. The .17 HMR gains roughly 5 to 10 fps per inch of added barrel up to about 20 inches, after which velocity gains essentially stop.
What is the best 17 HMR barrel length for hunting?
An 18 to 20-inch barrel is best for hunting, offering the ideal mix of sub-MOA mechanical accuracy and field portability.
What is the best 17 HMR barrel length for suppressed use?
A 16 to 18-inch barrel is best for suppressed shooting to prevent the rifle from becoming unwieldy when a rimfire suppressor is installed.