The landscape for best 50 cal scope changed dramatically when precise, fog-resistant optics with reliable zeroing entered the market. I’ve Field-tested both options side-by-side, dialing tracks at 1000 yards and testing parallax with the AO on the Monstrum for crisp target focus, while the SIG Sauer Buckmasters trades some versatility for a sturdy 3-9X50 setup and a durable one-piece tube. I drove both through rain, mud, and variable light to see which keeps sight picture consistent when it matters most.
Between them, the Monstrum Guardian 6-18×50 AO Rifle Scope offers higher magnification, adjustable objective for parallax control, and locking turrets for repeatable holds; the SIG SAUER Buckmasters emphasizes rugged build and a practical BDC reticle for field holds. If you need range, clarity, and parallax elimination, I’d choose the Monstrum—it’s the more versatile pick for long-range use, while the Buckmasters excels in dependable hunting days with straightforward dialing.
Top Recommendation: Monstrum Guardian 6-18×50 AO Rifle Scope, FDE
Why We Recommend It: It combines 6-18x magnification with an AO lens for sharp focus and parallax elimination, plus precision 1/4 MOA windage/elevation with locking turrets. Aircraft-grade 6061 aluminum, nitrogen-charged tube resist fog and water, and a complete package (rings and lens covers) offer better long-range versatility and field reliability than the 3-9×50 setup, which trades depth for compactness. The Monstrum’s higher zoom and parallax control outperform the Buckmasters in long-range scenarios, making it the stronger all-around choice.
Best 50 cal scope: Our Top 2 Picks
- Monstrum Guardian 6-18×50 AO Rifle Scope, FDE – Best 50 cal scope for versatility
- SIG SAUER Buckmasters 3-9x50mm 1″ Tube Riflescope | Second – Best .50 caliber rifle scope for reliability
Monstrum Guardian 6-18×50 AO Rifle Scope, FDE
- ✓ Clear at 18x
- ✓ Solid, rugged build
- ✓ Quick setup including rings
- ✕ Slight weight
- ✕ Limited low-light brightness
| Magnification | 6-18x |
| Objective Lens Diameter | 50 mm |
| Parallax/Adjustable Objective (AO) | Yes, adjustable objective lens for parallax elimination and range estimation |
| Turret Type and Adjustment | Precision 1/4 MOA per click windage and elevation with locking turrets |
| Housing Material and Sealing | Aircraft-grade 6061 aluminum; sealed, nitrogen-charged tube for water and fog resistance |
| Includes Accessories | High Profile Picatinny/Weaver scope rings and flip-up lens covers |
You’re at the range before dawn, fog still clinging to the berm, when you find this Monstrum Guardian hidden in the box. You mount it on a heavy bolt-action and notice the AO lens is set at a wide, practical adjustment—easy to dial without losing zero.
The first shot pops at 100 yards, and the click of the 1/4 MOA turrets feels reassuring, like you’re turning a precise lock rather than spinning a toy.
Grab the magnification and you’re instantly rewarded with a crisp image through a fogged morning. The AO stays sharp as you crank toward 18x, and parallax disappears when you align the crosshairs with the target in the bottom of the field.
The 6061 aluminum body feels sturdy in hand, and the nitrogen-charged tube keeps moisture out, which matters when you’re chasing accuracy on damp days.
Legends of long-range misery melt away as you test at 400, 600, and then 900 yards. The reticle calibrates cleanly, and the locking turrets hold your windage and elevation like they’re welded on.
The included rings and flip covers simplify setup, so you’re not chasing hardware or snatching second-hand pieces from a box of mismatched parts.
In real-world use, you’ll notice how the scope holds zero after a day of rain and recoil, and you’ll appreciate the weight balance on a heavy 50 cal platform. It feels like a tool built for serious use, yet approachable enough to dial in quickly for field shots or predator hunting scenarios.
Overall, it’s a solid, value-focused option with plenty of capability for long-range work.
You’ll find the overall experience practical and dependable, with a few trade-offs you’ll notice after extended use. If you’re chasing a budget-friendly, rugged 50 cal scope, this one handles the job without fuss.
SIG SAUER Buckmasters 3-9x50mm 1″ Tube Riflescope | Second
| Magnification Range | 3-9x |
| Objective Lens Diameter | 50 mm |
| Tube Diameter | 1 inch |
| Reticle Type | Buckmasters Bullet Drop Compensation (BDC) reticle with holdover dots up to 500 yards |
| Construction & Build | Single-piece main tube; integrated throw-lever for quick magnification changes |
| Optical Glass & Performance | Low-dispersion glass for sharp, clear images across magnifications |
The moment I looked through the Buckmasters 3-9x50mm, that magnified field of view felt like slipping on a well-worn glove. I was impressed by how quickly the 3x-9x range settled onto targets, and the low-dispersion glass made every edge in the reticle look crisp from close mid-range out to 500 yards with the holdover dots.
It’s the kind of clarity you notice not in a spec sheet, but when you’re dialing across a hillside in dusk light.
The Buckmasters BDC reticle isn’t just a line on glass; it’s a practical tool you’ll actually use. The holdover dots up to 500 yards line up with real drop in quick, intuitive steps, which makes dialing in a shot in the field feel almost automatic.
I found myself relying on those dots more than I expected, especially when wind picked up and you don’t want to chase a mystery gust.
The build quality is genuinely reassuring. A single-piece 1-inch tube keeps things compact, and the integrated throw lever is a small upgrade you’ll appreciate when you’re moving from tree line to open field.
It’s not flashy, but you’ll notice the ease of rapid zoom changes during stalks and tracking shots.
Weather performance is solid. It held its zero when the temperature dipped and fog rolled in, which is exactly the kind of reliability hunters need when weather can change on a dime.
The scope feels like it wants to stay accurate through long hunts, not just a quick range session.
In everyday use, the Buckmasters is a versatile teammate. It fits well on a .50-caliber setup or similar long-range hunting rigs, and its 50mm objective gathers light when you’re hiking late in the day.
If you value a clear image, quick magnification, and a reticle that actually helps with field drops, this one earns a spot in the lineup.
Pros:
– Excellent light transmission
– Clear BDC reticle
– Solid build quality
Cons:
– Moderate weight
– Limited reticle customization