WP870 BUILD LOG

The Story

Ente has always been a firearms enthusiast and interested in history, especially World War I, World War II and The Vietnam War. Ever since he first used the Remngtion 870 in Call of Duty Black Ops II he wanted one of his own.

U.S. Marshal with WP870

Pictured escorting Bhagwan Shree Rajneesh to a hearing in Charlotte, North Carolina.

November 11th 1985

U.S. Marshal with WP870

Pictured providing court security during the trial of narcotics trafficker Carlos Lehder Rivas in Tampa, Flordia.

February 2nd 1987

What is a WP870?

The 12-Gauge shotgun is the longest-serving gun in the American law enforcement community and continues to be the most prevalent long gun in the armories of police agencies across the country. While most law enforcement shotguns are bland and unexciting, there are specific versions that hold a unique appeal. One of those is the "Witness Protection 870", or 'WP870'.

The original "Shockwave" type shotgun used by the U.S. Marshal Service beginning in the mid 1980s. These firearms were designed for the Witness Protection Program to be carried under cover of a jacket or trench coat and readily available against a close threat. They utilized the Remington 870 platform and the cutdown barrel lengths ranged from 12.5 inches to 14.5 inches. The original stock was reshaped to what's called a birdshead very similar to today's Shockwave grip.

The U.S. Marshals Service never called it the Witness protection shotgun. Instead, they called it the Marshal’s Service Short Shotgun. A Marshal named Lynn Jordall came up with the idea and worked with an armorer at Glynco named Gene Thompson to produce the first of these shorty shotguns. According to Thompson, he built the first prototypes, and when they decided to produce the shotgun en-masse, they contracted the creation of the bird’s head grips out to Jim Wilson of Wilson Combat. Wilson was young at the time, and he hadn’t formed his premier firearms company just yet.

The 'WP870' gains its nickname from its adoption and use by the United States Marshals Service. Fellow gun scribe Chris McLoughlin outlined the beginnings of the original guns in a 1984 article. According to McLoughlin, Gene Thompson, Lynn Jordall and Jim Wilson built three prototypes. This was a collaborative effort with each man working on a select feature to produce the most effective platform. The result was a cut-down Remington 870 with a 14.5-inch barrel, a custom-built hand stop and, most significantly, an ergonomic grip that retained the shape of the original factory stock. Other modifications included a slotted shell lifter to assist in clearing a short-stroke-induced double feed and a unique sling system.

The early version of the gun utilized Remington 870s with barrels trimmed to 14.5 inches and the cylinder bores modified to accept Mossberg pattern chokes. Around 240 of these guns were created and fielded for various roles in the Marshal’s Service, including Witness Protection. The U.S. Marshals Service created these specialized shotguns for close-range protection roles within the Witness Protection Program. They were designed for high firepower in tight spaces.

Jim Wilson was a talented machinist whose modest shop was located on Oriole Street in Brunswick, Georgia. Wilson saw the potential for other government, law enforcement and civilian sales of the WP870. Wilson provided two distinct services regarding the WP870. The first was a conversion of an agency shotgun. The second was to convert a customer’s personal 870 into a WP870. In 1984, the conversion cost was listed as $214.80. Because this was a conversion of a non-NFA shotgun, the BATFE classified it a short-barreled shotgun (SBS), which mandated a $200 tax stamp for individuals. Later, Wilson became a Remington manufacturer and received receivers and parts to build 50 guns. Since these were manufactured in the WP870 configuration, the BATFE classified these guns as Any Other Weapons, or AOWs, making them subject to a $5 AOW tax stamp. Unfortunately, the arrangement between Wilson and Remington did not continue, and no more WP870s were manufactured as AOWs.

As with the original design, the grip is manufactured from the original stock and is rounded to a bird’s head configuration. As with any combat shotgun, the shotgun was given a shorter pump to allow access to the loading port while the slide is in the rearward position. One of the marshals’ requirements of the Witness Protection 870 was that it be concealable under a jacket. The original designers came up with an ingenious solution to carry the 25-inch shotgun. The hand stop, which was installed at the end of the magazine tube to prevent the user’s hand from slipping in front of the muzzle, also served as a sling receptacle. A traditional sling swivel was installed at the rear of the pistol grip. The key to this system was the design of the sling. The designers utilized an M1 Carbine sling with a quick-release snap that was mounted to the hand stop. The shotgun could be slung under a jacket in an upside-down configuration. To present the shotgun, the user would grasp the pump with his or her support hand, reach across their body and unsnap the sling. This freed the shotgun, and the support hand pulled the gun from under the jacket for a reasonably efficient presentation.

The Marshals Service Short Shotgun brings compact firepower home without the cost of being an SMG. A short shotgun like this delivers a ton of power per pull of the trigger. Sure, the lack of a stock makes it tougher to wield, but it’s really not that hard to be efficient with practice. Pair it with the correct ammunition, and you can easily wield the weapon accurately. Moreover, contrary to popular belief, it won’t smack you in the face if you try to aim. In fact, you can shoot it with a single hand and not experience some crazy whip-like recoil.

While the original "Witness Protection" guns were heavily regulated National Firearms Act [NFA] items due to their short barrels, modern manufacturers offer similar configurations that are not classified as NFA weapons.

Why build one?

Ente always like the Remington 870 in Call of Duty Black Ops II and had the idea to build a shotgun visually similar to the ‘Sawed-Off’ from Counter-Strike. Recently Remington released the Model 870 Tac-14 Hardwood which is homage to the WP870. Since the release, unfortunately they seem to be out of stock all the time after 2 bankruptcies and buyout of the firearms manufacturing arm of the original Remington which is now RemArms.

Ente being the type of person to build what he wants, decided to get the parts together to build a short 870. Ente already had an 870 Reciever with a four shell magazine tube and he had an idea of a short 14-inch barreled shotgun with wood pump & hand grip and started looking around. He wanted to add a +1 shell extention to get magazine tube approxmately the same legnth as the barrel and to have to ability to mount a sling.

How did he do it?

Ente found Wilson Combat and they had lots of parts for the 870. He picked up the +1 extention, a Jumbo Safety for easier manipulation and a shell carrier to hold an additional 6 shells on top of the 5+1 capabililty of the 870 with the tube extention. After he started searching for wood furniture, specifically the wood ‘birdheads’ grip. After searching for that he found pictures of the Tac—14 Hardwood and the listing on Remington’s website. Ente thought it was neat that the exact concept he was trying achieve was already a commerical product.

After doing some more looking around for furniture Ente knew he wanted a ‘Corn Cob’ style pump, the old police style. He found a NOS [New Old Stock] Walnut Pump and ordered a wooden handgrip to match. After seing the Tac-14 Ente did some more reasearch and came across the story and use behind the WP870. This only made Ente want to build one even more since there is historical significance to the gun as well. When it came to the barrel Ente found that an 18.5 inch barrel is the most common and he was planning on purchasing one to cut down to 14 inches. He found someone selling a 14-inch barrel for an 870 that was blued and had a bead sight already installed. This saved him a bit of work and refinishing.

Ente found SladeStreetTactical while looking for parts and really liked their heat shields. They had a Tac-14 specific heat shield but it is polymer and Ente wanted a metal shield so it can gain finsih wear and patina with time. He found the 6-Hole 870 Metal heatshield in their shop and reached out to them to verify measurements. Chris responded and let me know it is 14 inches overall and there is a 1-inch tab that can be trimmed off to fit the 14-inch barrel properly. Ente found the rest of the parts on MidwestGunworks, which includes the bolt, bolt slide, fire control group, takedown pins, pump forend and nut.

Since the Receiver had a 4 shell tube and Ente wanted to install an extention there was some work to be done. In the magazine tube there are 2 dimples that prevent loading more than 4 shells which need to be flattened out or filed off to allow the shell to pass through. There is a tool made specifically for this but Ente measured a 12-Gauge shell at the base with a set of calipers and found a 5/8” spark plug socket that was a perfect match for the diameter of the shell base. Ente use a socket extention, a hammer, some oil and elbow grease to drive the dimples out of the magazine tube. Ente opted not to file the dimples becasue he didn’t want there to be holes in the magazine tube.

After getting that sorted out he installed the Walnut Pump on the forend, the barrel and pump forend on the receiver and married it all together with the +1 Tube Extention. Ente then installed the birdheads grip onto the receiver, installed the bolt, bolt slide and got those aligned with the pump arms. He got the fire control group in place and installed the takedown pins. Ente installed the heat shield after he got it trimmed and painted. The Shell Carrier is installed last, the crossbolts for the shell carrier go in place of the takedown pins. Ente removed one pin and installed one of the crossbolts with some Loctite (Do not use Red) then drove out the second pin and installed the other bolt.

Ater it was assembled Ente did a functions check at the workbench.

Ente built his WP870 for about $750 USD with new & used parts.

(Tools not included in that price.)

Receiver‍ ‍Remington $150

Bolt ‍Remington $125

Bolt Slide ‍Remington $20

Fire Control Group ‍‍Remington $100

Pump Forend ‍‍Remington $40

Pump Forend Nut ‍‍Remington $10

Barrel‍ ‍‍Remington $100

Tube Extension ‍ Wilson Combat $55

Jumbo Safety Wilson Combat $20

Shell Carrier Wilson Combat $35

Heat Sheild SladeStreetTactical $75

Furniture Remington $120(Free - Gifted)

Total: $750

Accessories

Ente got an M1 Seatbelt Sling in Black to be able to carry the shotgun and coincidentally it matches the orignaly WP870 sling.

Sling ‍USGI M1 Sling‍ ‍$20


After a few months of research, careful planning, sourcing parts and tools, the build was finished.

A list of parts and tools used can be found below. For those who want to build their own WP870.

Thank you for reading if you made it this far!

-Ente & Maltz

Founders of Functional Reserve Militia

Parts:

  • Remington 870 Receiver

    Receiver

    Remington

    870 Receiver

    Product Made in USA

  • 870 12Ga Bolt

    Bolt

    Remington

    870 12Ga Bolt

    Product Made in USA

  • 870 Bolt Slide

    Slide

    Remington

    870 12Ga Bolt Silde

    Product Made in USA

  • Wilson Combat Plus 1 Extension

    Tube Extension

    Wilson Combat

    Plus 1 Shell Extension

    Product Made in USA

  • 870 14inch 12Ga Barrel

    Barrel

    Remington

    870 12GA 14” Barrel

    Product Made in USA

  • 870 Heat Shield

    Heat Shield

    SladeStreetTactical

    870 6-Row Heat Shield (Trimmed)

    Product Made in USA

  • Walnut 870 Pump

    Pump

    Remington

    Walnut 870 Pump

    Product Made in USA

  • 870 Pump Forend

    Pump Forend

    Remington

    870 Pump Forend

    Product Made in USA

  • 870 Pump Forend Nut

    Pump Forend Nut

    Remington

    870 Pump Forend Nut

    Product Made in USA

  • 870 Wood Birdheads Grip

    Grip

    Remington

    870 Wood Birdheads Hrip

    Product Made in USA

  • 870 Jumbo Safety

    Jumbo Safety

    Wilson Combat

    870 Jumbo Safety

    Product Made in USA

  • 870 Trigger Assembly

    Fire Control Group

    Remington

    870 Trigger Assembly

    Product Made in USA

  • Wilson Combat Side Saddle

    Shell Carrier

    Wilson Combat

    Side Saddle

    Product Made in USA

  • M1 Seatbelt Sling Black

    Sling

    US GI Standard Issue

    M1 Seatbelt Sling Black

    Product Made in USA

Recommended Tools:

  • W Wiregear Pin Punch Set

    Pin Punch Set

    W Wiregear

    Pin Punch Set

    Product Made in USA

  • Building/Cleaning Mat

    Building/Cleaning Mat

    2F22E

    AR Building Cleaning Mat

    Product Made in China