Expo Arms Mil-Spec Steel Castle Nut
Click to see full view
Expo Arms
Overview
The Expo Arms Mil-Spec Steel Castle Nut is a standard component designed to secure the buffer tube to the receiver, ensuring stability and proper function during operation. Made from steel with a phosphate finish, this castle nut provides reliable durability that builders can count on in their AR-15 configurations. This part is commonly found in builds featuring a mid-length gas system chambered in 5.56 NATO, making it a versatile choice for a variety of setups.
Specifications
Available Merchants
Price Alert
Log in to set a price alert on this product.
No Available merchants at this time.
Build history on GunPartPicker
Builders on GunPartPicker first added the Expo Arms Mil-Spec Steel Castle Nut to a build in February 2026.
Updated · from real builds on GunPartPicker
Builds Featuring This Part
See all 1 →Builds in the community that include the Expo Arms Mil-Spec Steel Castle Nut
| Build | Parts | Total |
|---|---|---|
 | 24 | $1567.46 |
No reviews yet. Be the first to review this product!