Cooper-T

Cooper-T (also styled Cooper T. Products) was an American paintball equipment manufacturer and aftermarket parts supplier operated by Chauncey E. Toombs in Angola, New York. Active from at least the late 1980s, the business specialised in paintball marker conversions, replacement bolts and other mechanical components.[1][2]

Cooper-T was particularly known for its IMP semi-automatic conversion kits, which allowed existing Sheridan and WGP Sniper pump-action markers to be converted to mechanical semi-automatic operation. The company also developed patented breech-bolt technology and replacement components for Sheridan markers.[1][3]

History

Early operations

Cooper-T was operating in the paintball equipment industry by the late 1980s under Chauncey E. Toombs.

A United States patent application filed by Toombs on 4 November 1988 documented an improved breech-bolt mechanism for gas-powered paintball markers. The patent, US 4,922,640, was granted on 8 May 1990.[3]

Cooper-T subsequently developed aftermarket equipment for several established pump-action marker platforms, particularly those manufactured by Sheridan and Worr Game Products.

Original company advertising identified Cooper-T Products at 8010 Lake Shore Road, Angola, New York.[2]

IMP conversion system

One of the company's principal products was the IMP, a mechanical semi-automatic conversion system for existing pump-action paintball markers.

The IMP used a direct-blowback operating mechanism that automatically recocked the marker after firing, eliminating the need to operate the pump handle manually.

The original manufacturer advertisement described the system as operating from an open bolt using liquid CO₂. It also promoted a semi-external velocity regulator and the ability to return the marker to pump-action operation without extensive modification.[4]

Cooper-T marketed IMP kits for Sheridan/PMI markers and the WGP Sniper platform.

The original advertised prices were:

Sheridan/PMI IMP Kit: US$134.95.
WGP Sniper IMP Kit: US$174.95.

The manufacturer also advertised an optional back-bottle adaptor for the Sniper conversion.[4]

VintageRex dates the Sniper version to 1990, although its records do not establish a confirmed introduction date for the Sheridan conversion.[5]

Sterling conversion

Cooper-T also developed an IMP conversion for the British Sterling pump-action marker.

VintageRex documents the conversion but describes it as a possible prototype that did not enter regular production.

The archive contains photographs of a surviving example, although it does not establish how many were manufactured.[6]

Later products

Cooper-T continued developing aftermarket components for pump-action paintball markers after the introduction of the IMP.

Its products included replacement breech bolts for Sheridan markers, including the Sheridan PGP and later PGP2K.

A technical review published by the Stock-Class Paintball Network documented a Cooper-T PGP2K replacement bolt using a Delrin body and an adjustable forward plunger intended to reduce paintball breakage during firing.

The reviewer, Eric A. Six, reported that Toombs had manufactured approximately 150 of the replacement bolts at the time of the review, with a selling price of US$26.95.[7]

The company's precise founding date and subsequent operating history have not been fully established.

Paintball markers and conversion kits

VintageRex lists five entries under Cooper-T. Four concern the IMP conversion family, while the fifth documents a Sniper pump-action marker.[1]

Product	Documented year	Type	Description
IMP Kit Sheridan	Not established	Semi-automatic conversion	Conversion system for Sheridan and PMI pump markers.
IMP Kit Sniper	1990	Semi-automatic conversion	Blowback conversion for the WGP Sniper platform.
IMP Kit Sterling	Not established	Prototype conversion	Experimental conversion for Sterling pump markers.
IMP Kit	Not established	Semi-automatic conversion	General catalogue entry describing the Sheridan conversion system.
Sniper	Not established	Pump-action	Sheridan-valve pump marker with direct feed and removable barrel.

The general IMP Kit and IMP Kit Sheridan entries contain substantially the same description and specifications. They should not be treated as two confirmed independent products.[1][5]

IMP Kit Sheridan

The Sheridan IMP was a semi-automatic conversion for older Sheridan and PMI pump-action markers.

The kit replaced or supplemented the original pump mechanism with a direct-blowback assembly, allowing the marker to recock automatically after firing.

VintageRex records compatibility with Sheridan-style valves, a .68-calibre firing system, direct feed and constant-air operation.

Different-sized bolts were available to accommodate markers including the Sheridan PGP.[8]

The manufacturer's installation instructions document the replacement of several components in the original marker, including the hammer, bolt and trigger arrangement.[9]

IMP Kit Sniper

The Sniper IMP was designed for the WGP Sniper series of pump-action markers.

It used a similar blowback arrangement to the Sheridan conversion.

VintageRex records the following specifications:[5]

Specification	Detail
Model	IMP Kit Sniper
Catalogue year	1990
Calibre	.68
Action	Mechanical semi-automatic
Valve system	Sheridan-style
Feed system	Direct feed
Barrel	Removable
Gas source	Constant air

The original manufacturer advertisement described the kit as a removable conversion that could be installed with limited modification.

A surviving boxed Sniper IMP kit was documented by paintball historian Daniel Bacci in August 2012, providing evidence of the product's construction and original packaging.[10]

IMP Kit Sterling

The Sterling IMP was an experimental conversion for the Sterling pump-action marker.

VintageRex records a .68-calibre mechanical semi-automatic configuration using a Sheridan-style valve and constant-air operation.

The archive describes the design as a possible prototype and does not establish commercial production.[6]

Cooper-T Sniper

VintageRex also lists a marker simply named Sniper under Cooper-T.

The catalogue identifies it as a .68-calibre pump-action marker using a Sheridan-style valve, direct feed, removable barrel and constant-air operation.[11]

The relationship between this entry and the WGP Sniper conversion has not been established.

Breech-bolt technology

Patented breech bolt

Chauncey E. Toombs received United States Patent 4,922,640, titled Breech Bolt, on 8 May 1990.

The patent described an improved breech-bolt locking mechanism for gas-powered paintball markers.

The design incorporated ball detents controlled by an internal sliding plunger. Its stated purpose was to secure the bolt in the closed position while allowing easier operation and removal for cleaning.

An additional feature was the retention of the ball detents during disassembly, reducing the likelihood of losing small components.[3]

Replacement and backspin bolts

Cooper-T subsequently produced replacement bolts for Sheridan paintball markers.

The company's PGP2K bolt incorporated a Delrin body, locking-ball mechanism and forward plunger intended to position the paintball further from the valve's gas outlet.

A contemporary technical review documented the design and reported reduced paintball breakage during testing.[7]

Cooper-T also produced backspin bolt designs, including an undershot bolt for the Sheridan KP2.

A surviving example was documented by Paintball History in January 2019.[12]

Patent litigation

In 1990, Chauncey Toombs, trading as Cooper T. Products, initiated patent infringement proceedings against several paintball equipment businesses.

The case named Gayle Goss, trading as Aerostar West, and numerous other defendants, including Sheridan Products.

The proceedings concerned alleged infringement of intellectual property associated with a paintball marker breech bolt.[13]

On 23 July 1991, the United States District Court for the Western District of New York dismissed the claim against Sheridan Products because the court found that the district was not a proper venue for that defendant.

The ruling concerned jurisdiction and venue. It did not determine whether Sheridan had infringed Toombs' patent.[13]

References

External links