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Honorable Service: SIG Sauer M11-A1 Review

Honorable Service: SIG Sauer M11-A1 Review

The M11-A1 is a tribute to the M11, a compact service pistol still serving U.S. Armed Forces.

The M11 compact service pistol is the U.S. military's variant of the SIG Sauer P228. Though now retired from civilian duty, the P228 can still be found in the holsters of military law enforcement and investigative agencies, as well as security personnel and aircrews of the U.S. Air Force.

According to 2013 Department of Defense (DoD) records, more than 5,000 of these pistols are in active service. Though the M11 represents a U.S. Army designation, it wasn't given this National Stock Number (NSN) until June 5, 1991. In spite of its Army designation, ironically, the Navy was the first branch to adopt the P228 in 1989, the same year SIG Sauer introduced this model.

The M11-A1 features a set of SIGLITE night sights dovetailed into its stainless steel slide.

NSN 1005-01-340-0096 represents the pistol procured for the U.S. Army and Navy. The U.S. Air Force adopted NSN 1005-01-336-8265. The only difference between the two NSNs is that tritium-filled SIGLITE night sights are standard on pistols for soldiers and sailors. Airmen carry an M11 without night sight capability.

SIG Sauer developed an upgraded replacement for the M11, the SIG Sauer M11-A1, which is based on the P229.


From the P220 and the P225 came the line of pistols we now affectionately call the P-Series. A subject of great controversy, the P226 was nearly selected for the U.S. M9 military pistol contract. Created in 1983 for the Joint Service Small Arms Program (JSSAP), the P226 was developed from the P225 and given a longer barrel and an enlarged grip frame to accommodate a 9mm 15-round magazine per contract requirements.


Shortly after the M9 was selected, the need for a compact service auto was identified, and the Compact Pistol Program (CPP) was initiated. The intent was to find a pistol that was lighter and more easily concealed than the M9, and it was expected that this new pistol would replace the variety of small handguns in use by the investigative branches of the Army, Navy and Air Force.

Two manufacturers, Beretta and SIG Sauer, submitted X11 pistol candidates for the Second Technical Feasibility Test (TFT 2). As a result of the test performed at Aberdeen Proving Ground (APG) in Maryland, the SIG Sauer P228 became the M11 First Article Test (FAT) pistol. Testing commenced on December 6, 1991, and was completed on April 30, 1992. During the Army's reliability tests conducted at APG in January 1992, only a single malfunction was experienced in 15,000 rounds among three P228s submitted for testing.


In a lot of ways, the P228-based M11 is similar to the P226-based MK25, only dimensionally smaller. It carries the slide of the single-stack P225 but with a widened frame to accept a 13-round magazine. The M11 combines a short barrel with a short grip to achieve its compactness. Theoretically, the M11 with its double-column magazine should have a wider profile than a pistol like the P225.

However, when the M11 is compared with the single-stack classic, this isn't the case. Thanks to the design capabilities of SIG Sauer engineers, the M11 nearly has the same grip circumference as the P225 and newer P226. This gives its user a compact pistol with plenty of 9mm on tap, something most shooters look for in a carry gun. The reduced girth of the M11 also made it an ideal pistol for shooters with small hands needing to manage control of a high-capacity handgun.



I traveled to the Rock Island Arsenal Museum and was permitted to closely examine an XM11 and an M11 as benchmarks for comparing the SIG Sauer M11-A1. Located in this island fortress on the Mississippi River between Davenport, Iowa, and Rock Island, Illinois, the museum was founded on July 4, 1905. It is the second oldest U.S. Army museum. Although most of the XM11 testing was conducted at Aberdeen, I was informed that Rock Island Arsenal did perform certain parts of that evaluation.

As mentioned, the capacity of the original P228 and M11 is 13 rounds, but the SIG Sauer M11-A1 ships with three 15-round magazines. The increase in magazine capacity comes from the fact that the M11-A1 frame is based on the P229. The P229 was designed to interchangeably facilitate the then-new .357 SIG as well as the .40.

Due to the larger cartridges, the grip frame for the P229 was enlarged to accommodate them. The success of the P229 made the P228 redundant. Unlike original P229s, most models offered today feature an integral accessory rail under the frame. Therefore, the SIG Sauer M11-A1 should appease SIG Sauer customers looking for a P229-type 9mm without the need for a rail.

Like the original P228 design, users benefit from a compact profile and a more rounded triggerguard.

The slide on the SIG Sauer M11-A1 is very close in size and shape to the M11. However, the M11 is made of folded carbon steel and features a removable breechblock and internal extractor. Like all current SA/DA P-Series pistols, the SIG Sauer M11-A1 utilizes a one-piece, CNC-machined stainless steel slide with an external extractor.

Though the M11 enjoys a great reputation for reliability, its internal extractor is positioned between the interior wall of the slide and the breechblock. It was thought that debris and brass shavings could collect in this area and interrupt function of the extractor. This is less likely to occur with an external extractor, and should the extractor have to be replaced, it can be removed without further disassembly of the slide.

Besides the subtle differences like the ball-milled slide serrations on the SIG Sauer M11-A1 and more angular scallops cut below and behind the ejection port on the M11, the overall appearance and weight of the two slide variations are impressively similar. The M11-A1 does continue a few other features found on the M11 including many phosphate-protected steel parts and an aluminum-alloy frame with arched triggerguard.

Like the M11, certain small parts like the decocking lever are still given phosphate protection.

To aid in concealment of the P228, SIG Sauer broke P-Series tradition and reshaped the triggerguard. Instead of the squared, front hook-style guard on SIG Sauer's classics, the curved contour given to the P228 and the M11 continues with the SIG Sauer M11-A1. The only other P229 currently featuring this rounded triggerguard is the SAS model.

Though now machined instead of stamped, the shape of the M11-A1 trigger remains similar to the M11. The SIG Sauer M11-A1 trigger is arguably improved in that it is thinner and facilitates the Short Reset Trigger (SRT) system. With the SRT, the pistol is ready to follow a shot with a single-action pull that resets just millimeters after having the trigger completely drawn to the rear. The M11-A1 measures a consistent 4½-pound trigger pull on single action and roughly 11 pounds when pulling through on double-action mode. The M11 trigger pull is very similar on the trigger-pull gauge, but the SRT makes all the difference when it's time to shoot live ammo.

From this vantage point, you can see the serrated hammer spur that can be manually cocked, the rear sight that's durable for one-handed slide manipulation techniques and the roll pin used to secure the external extractor. The M11-A1 carries an added laser-engraved SIG logo on top of the slide.

The military's M11 and the SIG Sauer M11-A1 are both mechanically locked, short-recoil-operated pistols featuring an automatic firing-pin safety lock, a double-action trigger, a decocking lever and an external slide stop. As many already understand, the first shot can either be taken in double-action mode by simply pulling the trigger to fully cock and release the hammer system or in single-action mode, where the hammer can be manually cocked for minimal trigger takeup.

With the hammer cocked, the SIG Sauer M11 and M11-A1 can be safely placed in Condition One by depressing the manual decocking lever located on the left side in front of the slide lock. Though no manual safety lever is present on the M11 or M11-A1, many safety features are included and ensure that these models can only be fired by pulling the trigger.

The SIG Sauer M11-A1 is commercially available and comes in this hardcase with three 15-round magazines.

The SIG Sauer M11 and M11-A1 use very similar grip panels. Unlike older SIG Sauer pistols with sharp checkering on a plastic that often cracked, the P228 was given grip panels made of modern polymer and given molded stippling. The P228-labeled grips on the M11-A1 are less abrasive than the old checkered type, but they mimic sandpaper texture and do a better job of enabling a no-slip grip than the pebble texture on the military's M11 grips. Neither the M11 nor M11-A1 grips should snag when these pistols are used for concealed carry.

The SIG Sauer M11-A1 is different from the military-issued M11 in other ways. If you put the SIG Sauer M11-A1 on the scale, you'd find that it weighs 32 ounces with empty magazine — three ounces heavier than the M11. A laser-engraved SIG logo has been added to the top of the SIG Sauer M11-A1 slide, and a sticker featuring a UID label is adhered to the left side of the frame. No M11s I've seen on military display or in service had a UID label stickered to the pistol, so if your "smart tag" label wears with use or peels, as ours did, don't fret. It doesn't really add to the Mil-Spec authenticity of the M11-A1.

At 25 yards, the M11-A1 presents accuracy potential that is on par if not slightly better than the standard-issue M9 service pistol.


The M11 has always been known for its accuracy potential, providing that the operator is capable. Those troops who have had the opportunity to know both military-issued SIG Sauers tend to favor shooting the MK25 for its longer sight radius. But the longer barrel on the MK25 does not seem to make it more accurate than the M11. That being said, we did test this civilian SIG Sauer M11-A1 with military-issue 112-grain M882 FMJ ball.

Five five-shot groups averaged 3 inches from 25 yards on a benchrest. In 2012, Guns & Ammo tested the civilian MK25 with ammunition from the same lot and obtained a 2.18-inch average. That's nearly an inch difference on paper, so maybe there is something to gain for barrel length.


The SIG Sauer M11-A1 did produce better results than the MK25 with commercially available defensive ammunition. Both the 115-grain JHP from Magtech and the new Hornady Critical Duty with 135-grain FlexLock performed remarkably, with sub-two-inch groups. Though the military customer is stuck using ball ammo, any LE agency interested in issuing the M11-A1 would be well served to consider Hornady Critical Duty.

Given superior barrier-penetration results and that our 25-yard groups averaged 1¾-inch with an occasional 1½-inch cluster means that only a Hornady FlexLock bullet will be carried in the chamber of this M11-A1 going forward.

Though the M11 and M11-A1 do present a shorter sight radius than the P226-based MK25, most troops find uncompromised accuracy.

With performance testing complete, I moved to test the M11-A1 in a nightfire qualification with local law enforcement. The M11-A1 exceeded expectations with little given up at night. Not only are the SIGLITE night sights highly visible for sight alignment in low-light and no-light scenarios, rarely do you find a set of factory sights capable of reliable one-handed slide-manipulation drills such as these.


Don't buy the SIG Sauer M11-A1 because you think you're getting a P228 or a copy of the M11. Whether a safe queen or a carry pistol, the M11-A1 is a fine pistol that honors another. The M11 is more often preferred for carry over the M9 service pistol for its shorter overall size, smaller grip frame and weight. The P228 and M11 represented an achievement for SIG Sauer in providing the user with a reliable and accurate high-capacity compact semiauto. The SIG Sauer M11-A1 carries that torch.

These F/A-18 Hornet pilots of the U.S. Navy are two of many specialized service members who are issued the compact M11.

The fact that you get three magazines, night sights and superior corrosion resistance makes the SIG Sauer M11-A1 a great buy, and considering that the SIG Sauer M11-A1 will carry in many readily available holsters for the nonrailed P229 models makes it a winner.

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