Shotgun Review: Mossberg 940 JM Pro

Could Mossberg’s new 940 JM Pro be the ideal defensive shotgun?

Shotgun Review: Mossberg 940 JM Pro

When you think of fast shooting in the competitive shooting circuit, the name Jerry Miculek comes to mind first. It makes sense that the 940 JM Pro, developed in collaboration with World Champion competitive shooter Jerry Miculek, is likely the most heavily tuned go-fast factory shotgun available for the competitive shooter. What you might not realize at first glance, however, is that Mossberg has added some intriguing features that make the 940 JM Pro possibly the fastest and most reliable defensive semi-auto shotgun available as well. Top to bottom, this shotgun is designed and optimized for speed, accuracy, reliability and durability — which are just the attributes you want in a defensive shotgun.

Semi-auto shotguns for defensive use are not new, however, historically, pump-action guns have been favored due to reliability concerns. But in the last few years, highly reliable and fast-shooting semi-auto shotguns like the Mossberg 930 and this new 940 are converting a lot of defensive shotgunners to semi-autos. The tuning Mossberg has delivered on the 940 JM Pro should impress any defensive shotgunner.

Mossberg’s 930 was a shotgun many shooters ran hard, but it did like to be kept clean, which could be a problem for competition or defensive shooters. If you wanted to load the 930 fast, the magazine port really needed some inletting, and there were a few other design barriers that prevented it from keeping up with the Miculeks (Jerry as well as his daughter, competitive champion Lena).

The Miculeks have put heavy use on the previous 930 JP Pro series and knew major areas they wanted to focus on for the redesign. The new 940 JM Pro represents all those updates that included the gas system, loading port, point-of-aim/point-of-impact, overall product fit and functionality, sight system and choke system.

The new durable gas system is one of those key defensive attributes that supports reliable operation up to 1,500 rounds without cleaning. This is thanks to nickel boron-coated internal parts — the same coating used on premium AR bolt carrier groups to extend lubricity and reliability and simplify cleaning. A stepped and vented-spacer component has also been incorporated that keeps the gas system running fast by shedding any moisture or carbon buildup every time it cycles. The 940 will reliably cycle any type of quality factory-made 2 3⁄4- or 3-inch ammunition. Though in this ammo shortage we were not able to hit the 1,500 mark, we did shoot more than 200 rounds without a stoppage. Our test model ran all of the rounds we stuffed into the magazine, regardless of type or length.

Another important defensive shotgun feature is the ability to reload quickly. The 940 JM Pro features an enlarged and beveled competition-level loading port to support single and faster dual and quad loading techniques to reload up to the nine-plus-one-round capacity. Typically, a lot of custom Dremeling is required on the receiver to open up the loading port to reliably support modern speed-loading techniques. We used EZ8 Gunner Solutions shotshell holders to test out the quad-load functionality and had zero gripes, at least at my non-Miculek reload speeds. An anodized bright orange follower and an elongated, pinch-free elevator help with identifying an empty magazine and aid in reliable feeding. The elevator and shell catch have also been specifically designed to eliminate common pinch-points when running the gun fast.

For comfort and to ensure the gun lines up and fits the shooter, Mossberg added loads of adjustments and ergonomics into the shotgun, including an adjustable stock, streamlined forend, adjustable 1.25-inch-range length of pull, and adjustments for drop at comb and cast using incremental stock shims.

Mossberg engineers worked to design a new barrel-making process for the 940 that ensures more accuracy and consistent groups. To ensure a broad capability beyond just competition or defense, a full set of cylinder, improved cylinder and modified Briley extended chokes put pellets right where you want them.

Addressing the needs of the competitive and defensive shooter, the receivers are anodized for superior durability and include oversized contoured charging handle and bolt release button for quick manipulation during high-stress shooting.

As an amateur skeet and trap shooter, my scores soared once my shotgun was custom fit to my natural point of aim. The 940 is completely user-configurable for fit, offering out-of-the box adjustability for length of pull (13 to 14.25 inches), drop and cast adjustments via shims. To further improve tuning, the fiber-optic HIVIZ TriComp sight system can be tuned with nine user- interchangeable LitePipes, in three colors and three shapes of varied height, for superior sighting in any competitive environment. All these design features deliver a reliable, natural-pointing and fast-shooting shotgun. The addition of oversized controls improves handling on a competition- and defensive-focused shotgun.

Mossberg offers the 940 JM Pro in two models featuring 24-inch barrel lengths, 10-round total capacity, and matte blue finish on the barrels. Color options include a choice of black-and-gold theme or a black MultiCam stocked model. The black-and-gold model includes a tungsten gray-anodized receiver, gold-anodized bolt handle, bolt release button, magazine extension nut, safety button, trigger, and cocking indicator. The black MultiCam pattern we choose is at home in the field or on the range, and it looks the part of a defensive shotgun.

The lines have thoroughly blurred between what makes a great competition and defense shotgun. From a barrel perspective, most defense shotguns just have 6-inch shorter barrels than what you’ll find on the 940 JM Pro. Thankfully, the competition shooters push and abuse guns far more than the wide majority of defensive shooters. Even amateur 3-gun competitors will easily shoot thousands of rounds more per season than defensive shotgunners’ yearly training. If the 940 JM Pro is built for that type of abuse, it should also be the perfect defensive shotgun.


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