Feedneck press-fit modifications [ZDSPB Custom]

Custom work - Feedneck press-fit modifications

In a similar vein to the line of threaded feedneck adapters, I've also produced an assortment of adapters that can be used on marker bodies requiring a press-fit between the body and feedport. The adapters allow the use of a modern Empire-spec latching feedneck that was previously not available for older bodies using the press-fit feedport.

Press-fit feednecks were common in markers around the year 2000 (slightly older or newer) as it was an effective method to permanently attach a feedneck with minimal machining time. Press-fit adapters can be found on 2000 vertical feed Shocker Sport bodies, many types of WGP Autococker bodies, AGD X-Mag breech sections, and some other markers. Through measurement, I've verified that many of these marker bodies were meant to use a 7/8" diameter feedneck mount, which is meant to be pressed into a body bore around 0.005" smaller. I mimicked these sizes in my own modifications.

Fabrication of these mounts is similar to their threaded counterparts, with the exception that many of the press-fit adapters are meant to wrap around the outside of the bolt itself. If this is the case, the adapter requires an added element of milling onto its "bottom" surface. There are many ways to perform this milling but I perfer to mount a grid of adapters in the CNC mill then simply 3d-surface the bottom contour. This allows a nice assortment of parts to be milled at once, and the same workholding device can be used for any style adapter regardless of height or outside diameter.

Rounded milling on bottom of adapter

WGP Autococker adapter:
The first (and undoubtably most popular) press-fit feedneck adapter I made was for the 2000-style WGP Autococker vertical feed bodies. This adapter sticks up arond the outside of the WGP body siterail so it has plenty of support on both front and back.

Dust and gloss WGP adapters

WGP body without feedneck

Pressing the adapter into marker body

Finished modification

Below are some finished markers after the modification was completed. I've also made some shorter adapters that accomodate markers that no longer use a siterail.

Feedneck adapter on WGP Prostock

Feedneck adapter on WGP Outkast

Feedneck adapter on Freeflow Mini

Feedneck adapter on Shocktech SFL

Feedneck adapter on Evolution-X

X-Mag adapter:
Adapters for the X-mag breech follow a similar design as the WGP counterparts, with similar milling on the bottom to accommodate the bolt shape. These adapters are made with the same press-fit interference as the factory WGP bodies, so the same reliability seems to apply to both adapters.

X-Mag adapters

X-Mag adapter installed

2000 Shocker V-Sport adapter:
Shocker Sport markers from the year 2000 use press-fit feednecks. Making an adapter for these markers is very simple compared to the WGP and AGD versions, which both require milling on the bottom.

Shocker Sport adapter

Shocker Sport adapter installed

Impulse 09 adapter:
The newer Impulse markers don't normally use a press-fit feedneck, rather they were intended to use a feedneck held in place using a pair of tiny set screws with a close fit to the marker's feedport. This system became a failing point of the marker, but it was never fixed because the marker was discontinued. Markers suffering this issue feature a wobbling feedneck which loosens up over time, requiring periodic re-tightening. It didn't take long to realize I could mitigate this issue by using a new feedneck adapter pressed into the feedport, which effectively solves the wobble problem.

09 Impulse adapter (raw aluminum)

09 Impulse adapters for factory and Empire feednecks

09 Impulse adapter installed

I made a few variations of these adapters, depending on the situation:
1. Feedneck adapter to use an 09 Impulse factory/stock feedneck
2. Feedneck adapter to use an Empire feedneck, in case the original feedneck is damaged or missing. This option also allows the use of my no-rise Unilock feednecks.
3. "Oversize" adapters for both above versions, which are purposely made to fit a marker body feedport that has been worn out by the feedneck wobble. These feedneck adapters are identical except that their press-fit diameter is slightly enlarged (+0.007" larger diameter).