The .270" POST A4 FRONT SIGHT STEEL BLACK – Part No. 64507 is a Colt-manufactured front sight post designed for A4-style AR platforms that require a precise .270" sight height. Built from steel with a black finish, this post is intended as a direct replacement or upgrade component for AR-15, AR-15/M4, and M16 rifles that use a standard A4 front sight base. Brownells Norge+1
Product Overview
This front sight post is a post-style A4 front sight element used in fixed front sight bases on AR-pattern rifles. It provides a .270" nominal height, which is a common dimension for rifles that need slightly taller front sight posts to achieve proper zero with standard A2-style rear sights. Brownells Norge+2Brownells UK+2
Key characteristics:
Construction, Material, and Finish
The .270" A4 front sight post is constructed from hardened steel for durability in service, repeated adjustment, and long-term stability under recoil and environmental conditions. Brownells Norge+2Brownells Iberica+2
Construction details:
Material: Steel for a robust, wear-resistant sighting surface
Finish: Black protective finish to reduce glare and provide basic corrosion resistance
Origin: Listed as Made in USA in Brownells product data Brownells Norge+1
The steel body is intended to resist rounding or deformation at the sight edge, helping maintain a well-defined sight picture over extended use.
Height, Sight Picture, and Use with A2/A4 Systems
With a .270" height, this post is designed to work with A2/A4 sighting systems on AR-15 family rifles that need a slightly taller front sight element for correct elevation zero. Brownells Iberica+3Brownells Norge+3Brownells UK+3
Functional implications of the .270" height:
Helps bring point of impact and point of aim into alignment on rifles where standard-height posts bottom out before proper zero is reached.
Supports use with a variety of carry handles and detachable A4 rear sights that rely on front sight post height to complete the elevation adjustment range.
Maintains a familiar square-post sight picture typical of AR-15 iron sights.
Because front sight post height interacts directly with rear sight elevation settings, the .270" dimension is important for users tuning their iron-sight zero on specific barrel lengths and sight-base heights.
Platform Compatibility
Vendor and OEM-based specifications list this front sight post as compatible with a range of Colt AR-platform models, as well as general AR-15, AR-15/M4, and M16 pattern rifles using an A4 front sight base. Brownells France+3Brownells Norge+3Brownells Iberica+3
Typical compatibility includes:
Colt AR-15 Match Target
AR-15 Match Target Competition HBAR
AR-15 Match Target HBAR Brownells Norge+1
AR-15 / AR-15 M4 pattern rifles with standard A4 front sight bases
M16 and similar service-profile uppers that accept standard threaded front sight posts Brownells Norge+2Brownells Norge+2
The part is identified in multiple catalogs under Colt front sight post listings, confirming its role as a factory-style replacement for A4 front sight assemblies. Brownells Norge+2Ammo Supply Warehouse+2
Installation and Adjustment
The .270" POST A4 FRONT SIGHT STEEL BLACK threads into a standard A2/A4 front sight base and is typically adjusted with a conventional AR front sight adjustment tool or an appropriately sized instrument designed for four- or five-notch posts (tool not included in most listings). Wet Worx Outfitters+1
Installation and use considerations:
Threaded installation: Screws into the threaded socket in the A4 front sight tower.
Detent interface: Works with the existing front sight detent and spring to hold elevation settings under recoil (detent and spring sold separately on most sites). Brownells Norge+1
Elevation adjustment: Rotating the post raises or lowers the front sight, directly influencing point of impact.
For best results, installation and zeroing should follow standard AR-15 sighting procedures and any applicable armorer guidelines for the specific upper receiver and rear sight used.
Typical Use Cases
Because it is an OEM-style component, the .270" A4 front sight post is commonly used in:
Factory-Spec Replacement
Elevation Correction and Tuning
New Builds and Retrofits
In all applications, this part is intended as a non-optical, mechanical sighting component within a standard AR-pattern iron sight system.
Technical and Catalog Identification
For inventory management, ordering, and SEO purposes, the .270" POST A4 FRONT SIGHT STEEL BLACK can be identified with the following standardized data:
Using these identifiers ensures accurate matching when searching for “.270 A4 front sight 64507,” “Colt .270 front sight post steel black,” or cross-referencing the part in AR-15 front sight assemblies.
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