Flatline Ops HALO-X™ Precision Scope Bubble Level

Eliminate Cant. Eliminate Guesswork.

A rifle that's only a few degrees off level can introduce enough horizontal error to cause a miss at extended distances. As shooting distances increase, even a slight amount of rifle cant becomes increasingly significant, turning an otherwise perfect elevation solution into an unnecessary windage error.

A quality anti-cant level helps ensure every shot begins from a properly leveled rifle, allowing your ballistic solution to work exactly as intended.

The Flatline Ops HALO-X™ Precision Scope Bubble Level represents the latest evolution in anti-cant technology from Flatline Ops. Originally developed for Leupold's Mark 5HD military optic programs, including the U.S. Army PSR, M110, and MK22, the HALO-X brings military-inspired engineering to civilian precision shooters.

Designed to be lightweight, durable, and exceptionally visible, the HALO-X provides a precise reference for leveling your rifle without adding unnecessary bulk to your optic.

Technical Specifications

• Precision rigid scope bubble level
• Machined from 7075-T6 aerospace-grade aluminum
• Mil-Spec Type III hard anodized finish
• Weighs less than 0.5 oz
• Width: 5/16 in. (0.3125 in.)
• Vial-Bridge™ suspended bubble with reflective platform for enhanced visibility
• Jaw-Bone™ hinge design for simplified installation
• Single top-strap screw design
• Designed for both left- and right-handed shooters
• Available for:
  • 30mm scope tubes
  • 34mm scope tubes
  • 35mm scope tubes
  • 36mm scope tubes
• Made in the USA

Ally Munitions Notes

We're proud to offer another premium American-made product from Flatline Ops.

We've been running Flatline Ops bubble levels on our personal rifles for the past couple of years, and they've consistently impressed us with their quality, durability, and thoughtful engineering. Simply put, Flatline builds some of the finest accessories available for precision shooters.

A quality anti-cant level is one of those accessories that's easy to overlook until you begin shooting at distance. Once you've experienced the consistency that comes from starting every shot with a level rifle, it's hard to imagine shooting without one.

The HALO-X is lightweight, rugged, easy to install, and designed with precision in mind. Whether you're hunting, competing, or spending time on the range, it's an excellent addition to any precision rifle.

We're excited to make Flatline Ops products available to our customers and look forward to expanding our lineup with more of their outstanding American-made products in the future.

Ally Munitions Field Note

One of the biggest advantages of a scope-mounted bubble level is that it allows you to tune the rifle to your natural shooting position, rather than forcing your body to conform to a fixed reference.

Our recommended installation procedure is simple:

1. Install the scope and loosely mount the HALO-X.
2. Hang a plumb bob at a known distance.
3. Settle naturally behind the rifle in your normal shooting position.
4. Align the vertical crosshair perfectly with the plumb line.
5. Without disturbing the rifle, rotate the HALO-X until the bubble is centered.
6. Tighten the level according to the manufacturer's recommended specifications.

By setting the level this way, you're calibrating the rifle to your natural point of aim, rather than forcing yourself to adapt to an arbitrary level reference.

The result is a more comfortable shooting position while maintaining a truly level rifle every time you break the shot.

The HALO-X is also an outstanding choice for lightweight hunting rifles. When every ounce matters, its compact size and weight of less than half an ounce allow you to add an important piece of precision equipment without noticeably affecting the balance of your rifle.