'/%3E%3C/svg%3E){kind=small}
The Squire Bingham pump-action shotgun is one of the few shotguns of this type to feature a barrel screwed into the receiver. Throughout this article, we will cover the following points:
-
- Overview of the parts: receiver, barrel, bolt, magazine tube.
- The manufacturer made the barrel and the receiver a single permanent unit. Is it necessary to remove the barrel? If so, why and how should it be done? How do you reinstall the barrel after removal?
- How is the receiver of the Squire Bingham pump-action shotgun machined? Why is the bolt locking recess located in the receiver?
Overview of the parts
The receiver
The receiver of the Squire Bingham pump-action shotgun is made of steel. It is a heavy part, weighing: 858 grams.
It fits within a bounding box measuring: 188.5 mm x 63.1 mm x 34.6 mm.
For comparison, here are the bounding box dimensions of a Remington 870 receiver: 199 mm x 59 mm x 34.1 mm.
The stripped receiver, right side.
The stripped receiver, left side.
Inside the receiver:
Bottom view of the stripped receiver.
Right-side guide rails.
Left-side guide rails.
Top view of the receiver.
The two models disassembled for writing this article are different. I did not notice it at first glance, but one has a single action bar while the other has two. This can be seen in the photo below.
View of the front faces of two Squire Bingham pump-action shotgun receivers.
Front faces of two Squire Bingham pump-action shotgun receivers.
During the analysis of the firearm, I noticed that the rear of the receiver is a separate attached piece. One detail tipped me off: the sharp-cornered internal machining inside the receiver. This type of machining can only be achieved using specialized manufacturing methods, yet I doubt those would be applied to a low-cost shotgun from this brand. On the rear face of the receiver, rectangular weld marks are visible. I would say it is silver brazing or a similar process.
Rear face of a Squire Bingham pump-action shotgun receiver.
Below you will find photos of the rear of the receiver with and without the attached piece. Being able to make this comparison is a great opportunity, as these are not commonly seen views.
On the Remington 870, the manufacturer did not make this choice. The receiver is made from a single piece. It would be interesting to create a synthesis (physical or digital) between the Squire Bingham and the 870—namely, a pump-action shotgun featuring a one-piece steel receiver and a fixed barrel. There would likely be pros and cons. To be seen… that is another topic.
Rear face of the Squire Bingham pump-action shotgun receiver.
Rear plug of the Squire Bingham pump-action shotgun receiver.
Rear face of the Squire Bingham pump-action shotgun receiver.
Rear face of the Squire Bingham pump-action shotgun receiver.
The bolt locking recess is machined directly into the receiver. This could be an issue if the barrel were removable by the user. One would then have to ensure the part was properly fitted so that headspace remained within tolerances. Here, the problem is solved by having the barrel permanently secured to the receiver.
The bolt
The bolt and the locking block are a single piece. The locking block is the small angled projection located at the rear, on top of the bolt. At the end of its forward travel, the rear of the bolt tilts upward and engages its recess (in the receiver).
The bolt of the Squire Bingham pump-action shotgun.
Right side of the bolt.
The barrel
The steel barrel is cylindrical. It has neither a bolt locking recess nor an attached barrel ring connecting it to the magazine tube. It is simply screwed into the receiver (no threadlocker, no pin, no set screw).
View of the rear face of the Squire Bingham pump-action shotgun barrel.
Chamber mouth of the barrel.
The outer diameter at the chamber is: 30.5 mm. CIP standards specify a minimum chamber diameter for 12 gauge of: 20.65 mm / 20.30 mm. This results in a wall thickness of approximately: 5 mm.
Markings on the stripped barrel.
Markings on the stripped barrel.
There is a flat machined along the bottom generatrix of the barrel. This is very useful, as it will allow us to firmly clamp the barrel to a rigid fixture during disassembly.
The thread diameter is: 27.8 mm.
The thread pitch is: 24 threads per inch (TPI), or 1.058 mm.
The length of the threaded shoulder is: 16.8 mm.
Photo of the barrel threads on a Squire Bingham pump-action shotgun.
Close-up of the barrel threads.
The magazine tube
The magazine tube is screwed into the receiver. To remove the forend, the magazine tube must be unscrewed from the receiver. This is due to the presence of a retaining collar and a spring on the exterior body of the magazine tube. These prevent the forend from being removed from the front. It must slide off the rear of the magazine tube, so if you want to clean your firearm properly from time to time, you have to remove the magazine tube.
View of the magazine tube parts that prevent front removal of the forend on the Squire Bingham pump-action shotgun.
The magazine tube, its collar, and its spring.
Four holes at the front of the magazine tube (two of which are used for the magazine cap screws) can be used for this purpose. This is easily done with little effort using a pin punch or a screwdriver. The tube is not glued to the receiver.
When buying a used firearm or during periodic maintenance, detaching, cleaning, and greasing it certainly cannot hurt.
Barrel removal
User-level disassembly does not include removing the barrel. This is a deliberate choice by the manufacturer. Why should we go beyond the manufacturer’s intent? If the firearm is new, very well maintained, or still under warranty, I believe it is inadvisable to separate the two parts. On the other hand, if the firearm requires a deep overhaul—such as re-bluing, heavy rust removal, bore polishing, sandblasting, or reaming the chamber to magnum—then removing it becomes necessary.
Receiver and barrel before disassembly, right side.
Receiver and barrel before disassembly, left side.
To avoid damaging any parts and to clear the necessary workspace prior to barrel removal, remove the unnecessary components:
-
- The buttstock;
- The magazine tube/barrel clamp;
- The magazine tube cap (held by two screws);
- The trigger guard assembly;
- The bolt;
- The magazine tube;
- The forend.
Required tools:
-
- The receiver fixture (receiver side);
- A rigid clamping block (barrel side);
- A torque wrench.
The fixture mounted on the receiver:
View of the receiver / barrel assembly ready for disassembly.
The receiver / barrel assembly mounted in its rigid fixture ready to be disassembled.
The method:
The first barrel broke loose at 220 N·m. On the second one, a torque below 190 N·m was sufficient.
Barrel installation
Index mark on the front face of the receiver.
We will use two witness marks present on the firearm that were made specifically for this purpose. The first is on the receiver, and the second is on the barrel. As you may have guessed, using the tools mentioned above, you must align both marks.
Index mark on the barrel.
Index marks after reinstalling the original barrel.
Before torquing, preparatory work must be carried out (cleaning the parts, removing burrs, greasing the threads, hand-tightening until it bottoms out against the receiver, inspection…).
Conclusion
Disassembly and reassembly are straightforward. There is no reason to hold back from giving firearms in need a proper rejuvenation. If you do not wish to do it yourself, have it done by a professional.
The locking recess is carried by the receiver. This is made possible because the barrel is not user-removable. Otherwise, headspace would have to be checked to stay within the tolerances defined by CIP standards, or the locking recess would have to be integrated into the barrel, as is the case on many pump-action or semi-automatic shotguns.
The trigger group is conventional. I chose not to cover that topic here. I may have the opportunity to do so at a later time.
The Squire Bingham pump-action shotgun is a heavy-duty, rugged firearm. It is built to last, provided it is properly maintained and refurbished when necessary.
A technician must look for engineering details in everything and at all times. Even if you do not own a Squire Bingham pump-action shotgun, I hope this article has sparked your curiosity.
If you like Gunsmith designer articles,
spread the word,
share this article.
To remove this part, the takedown lever must first be removed. This is not straightforward, as we will see later. The locking block is held in its housing by two pins, one of which serves as the pivot pin for the trigger and the slide stop.
The cylindrical section has an outer diameter of 14 mm.
The magazine is manufactured by MEC-GAR. It is very well finished. The body is made of steel, while the follower, locking plate, and floor plate are made of polymer. It disassembles very easily.
