Inside the Springfield M1A Underlever Pellet Rifle
As part of HAM’s recent simple refinishing exercise of the Springfield M1A underlever pellet rifle stock, we popped the action out of the stock.
Given that underlever pellet guns are not very common – particularly in 2022 – it’s interesting to look at the gun’s action and gain some idea of how it works. In addition, we’ll see why extra care is required when loading pellets in this type of airgun.
The Underlever Action
The big difference between an underlever air rifle and the more common breakbarrel type is that the barrel is fixed in the action.
Because the barrel does not move during cocking (or for any other reason), many people feel that it must be inherently more accurate than a breakbarrel, where the barrel pivots every time the gun is cocked, being locked back into position by a catch after cocking. Instead, underlever air rifles are cocked using a lever under the barrel. In other words, an – er – underlever.
This accuracy argument may be true as the Springfield M1A Underlever pellet rifle proved to be very accurate on test. In addition, some of the most accurate spring/piston air rifles like the Weihrauch HW97 and AirArms TX100 are underlever-cockers, too.
However, there is also a downside and that has to do with safety. With the fixed barrel, pellets must be loaded into an aperture in the top of the action.
In the case of the Springfield M1A Underlever pellet rifle, pulling down on the underlever compresses the powerful spring inside the gun. It also opens the loading port in the top of the gun as the “handguard” is driven forward, as shown in the photograph below.
Once the underlever is pulled right down, the loading port is fully exposed and the pellet is loaded directly into the rear of the barrel as shown below.
Here it is in closeup…
So it’s clear that the shooter’s fingers must go into the open action to load the pellet.
For this reason the Springfield M1A Underlever pellet rifle – like all other spring/piston and gas ram airguns – is fitted with an “anti-bear trap mechanism” that holds the spring back under compression when loading.
IN SPITE OF THIS, THE COCKING LEVER MUST ALWAYS BE TIGHTLY HELD IN YOUR HAND AS AN ADDITIONAL SAFETY MECHANISM WHEN LOADING PELLETS. THIS IS CRITICAL WITH ANY UNDERLEVER-COCKING AIR RIFLE. SHOULD THE PISTON FLY FORWARD UNINTENTIONALLY, YOU’RE CERTAIN TO HAVE YOUR FINGER CUT OFF, IF NOT WORSE!
But even before that, the user must push down on the cocking lever release located on the left side of the breech. The underlever cannot be deployed until this is done.
As we can see below. The cocking lever release handle is connected to a stout-looking steel assembly that’s wrapped around the trigger mechanism.
After the cocking lever release is depressed, the lever can be pulled down. To make the cocking action easier on the Springfield M1A Underlever pellet rifle, the lever can be extended, as shown below. This increases the mechanical advantage, reducing the cocking effort for the user.
In the case of the M1A, pulling down the underlever rotates two toothed wheels, one either side of the lever. These toothed wheels engage with the handguard and drive it back and forth. That’s how the handguard moves forward for loading. It’s an unusual way to achieve this result, but it seems to work just fine!
Looking up underneath the action, we can see the spring and piston through the slot in the underside of the compression tube. At the bottom of the photograph the non-functional “charging handle” assembly can be seen.
On the Springfield M1A Underlever pellet rifle, this is definitely for “show” rather than for “go”. It provides no real functionality associated with cocking, loading or firing the air rifle.
So this is how the cocking and loading mechanism of the Springfield M1A Underlever pellet rifle functions. For full details, it’s essential that the shooter reads Air Venturi’s User Instruction Manual. So RTFM, be safe rather than sorry. With due care, the M1A underlever pellet rifle can be a lot of fun to shoot!