SIG Airgun Secrets – Part One, Overview

This is the first of a four-part series on SIG airgun secrets. In fact, we’re dealing specifically with “long” SIG airguns, not the pistols.

Before we start, I should make clear that this is a series about the design differences between the SIG long airguns. We’ll look in detail at the CO2-powered MPX, MCX and Canebrake, as well as the HPA-powered Virtus.

Especially, this is NOT a repair guide to these guns. Sure, we’ll be looking inside them, however I strongly suggest that owners do NOT attempt to repair long SIG airguns. They’re complicated and require very careful disassembly and re-assembly.

Warnings over, let’s start to investigate what makes these popular airguns tick!

1. The Models:

There are four SIG long airguns. These are the MPX, MCX, Canebrake and Virtus models. Below we see the MPX, MCX and Virtus. That’s the Canebrake in our heading photograph above.

I was initially surprised to find that there’s two basic designs of SIG long airguns.

One design – the first – covers the MPX and MCX models.

The second design is used by the Canebrake and Virtus. As we’ll see in this series, internally there’s a considerable number of differences between these two designs.

Particularly, it’s important to know that the CO2-powered Canebrake shares the design of the HPA-powered Virtus. It’s not just a MPX/MCX painted tan with some different furniture on it!

That explains why the Canebrake is more powerful than the MCX, in spite of having a shorter barrel. Also why it is more expensive.

In addition, SIG has incorporated some improvements on a “running” basis throughout the range.

For reference, check-out these HAM reviews of SIG long guns.

First the original MCX from 2015. The newer models have come a long way since then!

Then the Virtus, SIG’s first .22 cal and first PCP.

Here is the Canebrake.

And the latest MCX Gen 2.

2: Clamshell Construction:

All SIG long airguns are of clamshell construction. They have two metal sideplates which contain the action when clamped together by numerous screws. In each case, the gun is assembled laying of the left sideplate.

Here’s the right sideplate for the MCX. In this model, the clamshell is held together with 9 small screws. In fact they’re metric M2.6 and different lengths are used in different places.

SIG Airgun Secrets

Here’s the MPX sideplate. Again, 9 screws are used for assembly but there’s no forward assist and the molded ejector port cover is sized for 9mm cartridges.

SIG Airgun Secrets

The MPX and MCX both use identical left side plates, with identical actions.

Below we see the side plate that’s used by the Virtus and Canebrake. It is held in place by 8 screws. Again, they’re M2.6 of various lengths.

SIG Airgun Secrets

Note that the Virtus/Canebrake sideplates use a separate Picatinny rail. The MPX/MCX sideplates incorporate the Picatinny rail “teeth” in the sideplate molding itself.

Turning over any of these sideplates reveals a highly-complex molding. In fact, the action fits into slots and holes in the sideplates. There’s also plenty of reinforcing ridges, too.

SIG Airgun Secrets

On the second part of this story on SIG airgun secrets, we’ll examine the firing system.

Check out the other parts of this series from these links: Part Two. Part Three. Part Four.

SIG Sauer MPX Pellet Rifle Gen 2, Black 0.177
SIG Sauer MCX Pellet Rifle Gen 2, Black 0.177
SIG Sauer MCX Rattler Canebrake CO2 Pellet Rifle 0.177
Sig Sauer ASP MCX Virtus PCP Air Rifle 0.22