You’ve never seen a Swiss K31 like this before…

The Sureshot Armament Group (SAG) has developed a modular aluminum chassis for the vintage, straight-pull Swiss K31 rifle. This chassis transforms an old classic into a modern, fast-cycling tactical rig. The SAG Lightweight K31 Rifle Chassis is CNC-Machined from aluminum. Hard anodized, it weighs just 2 lbs. 13 ounces. It offers adjustable cheek piece and butt-pad, with a three-inch LOP adjustment range. Believe it or not, installing a vintage K31 into this SAG stock is an easy bolt-on process. No modification of the K31 action is required.

The chassis-builder SAG states: “The main idea behind the SAG Lightweight K31 Rifle Chassis was to give the shooter …ergonomics of a Tube-gun but with lines of the classic rifle. The chassis ‘wraps’ the shooter around the rifle, moving bolt operation under the shooters cheek to allow the marksman to maintain cheek weld during the whole shooting series.” The chassis design also allows a more forward optics placement for better eye relief.

SAG Lightweight K31 Rifle Chassis Features:
CNC-Machined Aluminum with hard-anodized matte finish
Easy bolt-on installation to Swiss K31
Adjustable Cheek Piece (0-30mm)
Adjustable Buttpad to set LOP (11.5” – 14.5”)
KEYMOD Interface on fore-end and buttstock
Accepts any AR-type pistol grip
Overall chassis weight: 2 lbs. 13 oz. (1280 grams)
Chassis MSRP: €950 ($1163.00 USD)

About Switzerland’s Original Karabiner Model 1931 (K31)
The Karabiner Model 1931 (K31) is a magazine-fed, straight-pull bolt action rifle. It was the standard issue rifle of the Swiss armed forces from 1933 until 1958, though examples remained in service into the 1970s. It has a 6-round removable magazine, and is chambered for the 7.5×55mm Swiss Gewehrpatrone 1911 cartridge (aka GP 11).

Wiki Photo by Bouterolle, CC BY-SA 3.0

Although the K31 is a straight-pull carbine broadly based on previous Swiss “Schmidt–Rubin” service rifles and carbines, the K31 was not designed by Colonel Rudolf Schmidt (1832–1898) as he was not alive in 1931 to do so. Mechanical engineer Eduard Rubin (1846–1920) was the designer of the 7.5×55mm Swiss ammunition for which previous Swiss service rifles and the K31 are chambered. The Karabiner Model 1931 was a new design by the Eidgenössische Waffenfabrik in Bern, Switzerland under Colonel Adolf Furrer (1873–1958). The Karabiner Model 1931 replaced both the Model 1911 rifle and carbine and was gradually replaced by the Stgw 57 from 1958 onwards.

Could you hit a buffalo at 1.27 miles (2240 yards) … with iron sights? Impossible as that may seem, that’s exactly what Ernie Jimenez did last month at the North Springs Shooting Range in Price, Utah (elevation 5,627′). Shooting a milsurp Swiss K31 rifle chambered for the 7.5×55 Swiss round, Jimenez placed four hits on a three-foot-high, bison-shaped steel target placed a staggering 2240 yards from the firing line. Not bad for a rifle which Jimenez acquired many years ago for just $99.00. Of course he did have plenty of misses along the way (and Ernie even managed to hit the plate shielding his camera).

This video is set to start half-way through, when the shooter starts making hits:

The whole process was recorded on video and posted on YouTube. The Long-Range Shooters of Utah say this is an official Guinness World Record for longest shot with iron sights. We can’t confirm that, but it still is an impressive feat. Jimenez had to compensate for a huge amount of bullet drop. His K31’s long-range military sights helped but he still had to aim well over the pink bison. To see how far that target is, watch the video at 14:30 — a camera at the firing line zooms all the way back until the bison is nothing but a tiny dot. The photo below show the target at 8X magnification, but it’s still barely visible.

Magnified 8X view looking down-range at buffalo target.

Here’s the unmagnified, “naked-eye” view from the firing line. Can you see a pink buffalo?

Bullet Dropped Over 400 Feet along its Trajectory
To roughly gauge the bullet drop, we took a 7.5x55mm Swiss load from the Hodgdon Reloading Center. With max “book” load of H4350, a 168gr Sierra HPBT has a muzzle velocity of 2524 FPS. According to JBM Ballistics, that bullet will drop over 400 feet during its flight. That’s lot of hold-over! Assuming a 100-yard zero, 59° temp, and 5,600′ altitude, JBM calculates that the drop to 2250 yards is a stunning 210.9 MOA — that’s 4969.9 inches, or 414.15 feet!

In the first part of the video, shooter Ernie Jimenez talks about his hand-loads and his K31 rifle. Here is an example of the distinctive straight-pull K31 (Karabiner Model 1931). Image courtesy AIM Surplus.