SKU: 1501743
UPC: 745167143831
MPN: AA-SI-00004
The Altra Insert and Outsert .166 400 Spine delivers a precision arrow component system built for hunters and competitive archers who refuse to compromise on accuracy. Part of Altra's Reinforced Concentric Outsert System, this two-piece assembly addresses one of archery's most persistent challenges: maintaining perfect alignment between your shaft and broadhead. The insert seats deep into 166-diameter arrow shafts while the outsert threads securely onto the insert, creating a unified connection point that keeps your broadheads flying true. For archers building custom setups or upgrading existing arrows, this component provides the foundation for consistent downrange performance.
Altra machines these components from 7075-T6 aluminum alloy, the same aerospace-grade material used in aircraft structures and high-stress applications. The insert seats to a depth of 0.875 inches within the shaft, while the outsert encapsulates the leading edge at 0.43 inches, creating exceptional durability at the arrow's most vulnerable point. Pre-installed rubber O-rings serve dual purposes: they lock the outsert firmly in place and dampen vibration that can affect arrow flight. This design improves concentricity between insert and outsert, which translates directly to tighter groups at distance. The system also accepts micro insert weights for fine-tuning front-of-center balance without swapping components.
Whether you're chasing whitetails from a treestand or shooting 3D targets on the weekend circuit, the 400 spine rating suits mid-weight draw setups common in hunting applications. Each 12-pack weighs 50 grains total, giving you enough components to outfit a full quiver with spares. The threaded connection between insert and outsert allows for quick broadhead changes in the field without tools or adhesives. Browse our full selection of shooting accessories and hunting gear to round out your archery setup for the upcoming season.
This insert and outsert system is designed specifically for Altra Arrows 166-diameter shafts with a 400 spine rating. The precise tolerances are matched to Altra's shaft specifications for optimal concentricity and fit.
The outsert threads directly onto the insert after the insert is secured in the arrow shaft. Pre-installed rubber O-rings help lock the connection in place and reduce vibration during flight. No adhesives are required for the outsert-to-insert connection.
Yes, the Altra insert accepts micro insert weights, allowing you to fine-tune your arrow's front-of-center balance without replacing the entire component. This makes it easy to adjust arrow performance for different broadhead weights or shooting situations.
7075-T6 aluminum alloy offers an excellent strength-to-weight ratio and resists deformation under impact. It's the same grade used in aerospace applications, providing durability at the arrow's point of contact without adding unnecessary mass to your setup.
Each package contains 12 insert and outsert assemblies with a total weight of 50 grains for the complete set. This quantity covers a full quiver plus spares for the season.
WARNING ⚠️ You must be 18 or older to purchase shotgun or rifle ammunition and 21 or older to purchase handgun ammunition and firearms. Please reference our requirements for ammunition orders to "restricted" states HERE. Always make sure you use the correct ammunition for your firearms. Ammo cannot be shipped to a PO Box. Please reference state & local laws before making a firearm or ammunition purchase.
