Editing Delta Archery (section)

== Marker development ==

=== Millennium operating system ===

The Millennium retained the basic mechanical system of the Kingman Spyder.

Its stacked-tube arrangement used a reciprocating bolt and hammer, with gas pressure returning the mechanism to its cocked position after firing.

The marker could use components compatible with earlier large-striker Spyder designs.

Historical collector research identifies multiple Millennium body configurations, including versions with top, side and rear cocking arrangements.[5]

Both complete markers and receiver assemblies intended for custom Spyder builds have been documented.

=== Original Defiant design ===

The original Delta Defiant was mechanically distinct from the production Defiant.

Its experimental operating system used pneumatic pressure to recock the marker after firing, while retaining mechanical trigger control.

The ram assembly was incorporated inside the receiver instead of being positioned externally.

The prototype also employed a low-pressure pneumatic system and a valve arrangement intended to improve gas flow.[7][8]

Although the design reached advanced prototype testing, the available historical records do not establish commercial production.

=== Production Defiant ===

The production Defiant adopted the electropneumatic system developed for the Indian Creek Designs Bushmaster 2000.

It featured a vertically stacked receiver, electronic trigger control and pneumatic cycling.

The Defiant differed from the standard Bushmaster in its external milling, anodising and selected components.

VintageRex describes the production marker as using Autococker-compatible barrel threading and a pressed-in feedneck.[12]

The relationship between the two designs is documented in contemporary tournament reports from 1999.[9]