Skip to main content

Mossberg 940 JM Pro Semi Auto Shotgun Review

Mossberg's new 940 JM Pro is one fast race gun.

Mossberg 940 JM Pro Semi Auto Shotgun Review
Photo by Mark Fingar

There have been shotguns made for almost every need. I suggest “almost” because as long as the scattergun has been around, it has been customized to meet specialized needs. Engineers at O.F. Mossberg & Sons have created another shotgun that’s certain to catch the eye of more than one crowd. If you’ve pined over the idea of an over-­the-­counter “shotty” to meet your 3-­Gun needs, the Mossberg 940 JM Pro may be the one.

From woods and waters, to law enforcement and home defense, shotguns still play a considerable role in the world of firearms. There is no doubt in my mind as a former Special Weapons and Tactics (SWAT) operator, that shotguns are a frontrunner in the application of force. From the most violent suspects to breaching doors, shotguns get the job done, sometimes solely by intimidation. Then there are all of the competitive disciplines. Shotguns will never become obsolete.

It was sometime in late 2018 when I became aware of Mossberg’s pursuit to make an out-­of-­the-­box, 3-­Gun-­ready shotgun — a complete system that fixes anything that came up short on their 930 JM ­Pro Series. This was much anticipated news, as I happen to be the owner of more than one imperfect 930. The news was made only more interesting by the fact that the “First Family of Shooting,” Jerry Miculek’s family, would be involved.

Mossberg 940 JM Pro
The Mossberg 940 JM Pro is based on what Jerry and Lena Miculek felt was necessary to make the 930 appropriate for 3-­Gun competition. (Photo by Alfredo Rico)

A 3-­Gun shooter myself, I’ve tried to fashion a cost effective, reliable shotgun to meet my competitive needs, but I ended up angry, frustrated and relieved of hard-­earned money. The modifications necessary to bring the 930 JM Pro up to speed, as well as the constant maintenance to create necessary reliability, made me wonder if it would ever happen.


Trying to make a sporting or field gun meet the demands of 3-­Gun is costly and requires technical knowledge. Extended magazine tubes for capacity; enlarged controls to ease operation under stress; accurizing for long-­range slug engagements; and the potentially disastrous cutting away of receiver material for specialized loading techniques are all mandatory for making a field gun a 3-­Gun shotgun. Mossberg attempted this with the 930 JM Pro, but it didn’t meet some of those requirements. Also, there’s the issue of fit. Length of pull, drop at the comb, and cast are not easily changed on many shotguns, especially those with composite stocks. Enter the Mossberg 940 JM Pro.


Mossberg 940 JM Pro
The 940 offers slim furniture with new texturing. (Photo by Mark Fingar)

If, like me, you’ve longed for an over-­the-­counter, 3-­Gun-­ready shotgun, long no more. The newest addition to Mossberg’s shotgun line is not what the 930 JM Pro was. More than simply bearing Jerry Miculek’s initials, the new 940 action is a detailed, ground-­up build that’s sure to impress you and your wallet.

Gun School

Mossberg introduced the replacement of the 930 series at the Gunsite Academy (gunsite.com). The 940 JM Pro combines Miculek’s genius and ingenuity with appropriate factory installed accessories, engineering and value. Mossberg Engineer John Raciti was pleased to tell those of us in attendance, “We are proud to offer a complete solution when it comes to providing a 3-­Gun-­ready semiauto shotgun right out-­of-­the-­box. This is the first shotgun produced that can be quad-­loaded out-­of-­the-­box.”

Mossberg 940 JM Pro
Photo by Mark Fingar

He was right. I can’t find a mass-­produced shotgun capable of quad-­loading straight from the box. 3-­Gun ready, though? We’ll see.

Joining us at the Gunsite Academy were both Lena Miculek and her always pleasant father Jerry, smiling as they passed out the new shotguns to reviewers. The differences between the 930 JM Pro and 940 JM Pro were immediately visible. Lena even brought Load-­2 and Load-­4 shell holders for us to use on the range. First, we learned what makes the 940 different from its predecessor, and I can say that it’s much more than gold-­tone appearances. (In fact, it also comes in all-­black.)


Mossberg 940 JM Pro
The aluminum receiver is drilled and tapped for shooters to attach a rail and mount an optical sight. (Photo by Mark Fingar)

Presented to us was a dressed-­up model with a gray-­toned anodized aluminum receiver and gold-­anodized accents. Either version, the gray or the black, sports a newly designed 24-­inch vent-­rib barrel with a HiViz fiber-­optic front sight for rapid sight picture. Having a bright sight up front makes a difference when shooting fast by helping the shooter put the picture together quickly. If you don’t like the color, change it. Additional light tubes are included in a variety of colors. If you’re inclined, the receiver is drilled and tapped to mount a rail for your optic of choice.

Mossberg 940 JM Pro
The 940 JM Pro is equipped with the HiViz CompSight and comes with replacement red, white and green LitePipes. (Photo by Mark Fingar)

External improvements don’t stop there. From the black, extended Briley choke tubes — the 940 JM Pro comes with three — to the fully adjustable competition-­ready stock, there’s much to appreciate. For example, the machined and beveled feeding port was designed for any style of loading, but it is especially useful for quad-­loading. Also, notable is the slimmed down forend with its improved feel and ergonomics.

Mossberg 940 JM Pro
No tools are needed when changing the supplied Briley Accu-Choke extended tubes. The constriction is clearly marked. (Photo by Mark Fingar)

Obvious 940 JM Pro accessories include the oversized charging handle and bolt release for effortless manipulation. Both are as functional as they are good looking. It may not seem like much, but having the bolt release done at the factory saves a lot of the time and frustration in trying to drill and tap that little button perfectly. Closing the bolt quickly after reloading is the benefit.


Mossberg 940 JM Pro
The oversized charging handle and bolt release are large and functional. The gold anodized finish is optional on this model. (Photo by Mark Fingar)

Capacity isn’t just a concern for 3-­Gun, but a concern for snow goose hunters and anyone who wants the added capacity. The extended magazine is a two-­piece system fashioned together at the fore-­grip nut. The 940 JM Pro holds nine-­plus-­one rounds, the perfect number for shooting in the Tactical Optics division of 3-­Gun. Also notable is that the steel portion of the magazine tube connected to the receiver is coated in boron nitride (BN). If you know anything about gas-­operated shotguns, you’ll know that this can be a hard part to clean. BN keeps carbon from bonding to the metal.

Mossberg 940 JM Pro
Photo by Mark Fingar

The Mossberg 940 JM Pro’s loading port is factory enlarged and beveled specifically for quad-­loading with either a strong or weak hand. Even if you don’t quad-­load, rest assured that shucking two shells is really fast, and if you still load a shotgun one shell at a time, the shell lifter (i.e., elevator) has been modified to make it longer. This alleviates the dreaded thumb pinch or thumb-­nail cut when there’s just enough room for your thumb to get stuck between the elevator and the receiver.

Mossberg 940 JM Pro
The loading port has been enhanced for quad loading. Your thumb is safe from being pinched or cut, also. (Photo by Mark Fingar)

Shotguns work best when they fit the shooter. The 930 version had the ability to adjust the drop at the comb. The new 940 has adjustability for this, as well as cast on and off and length of pull. Maximizing performance through proper fit requires a modern system or an expensive and experienced craftsman. Proper stock fit helps in shooting more comfortably and alleviates getting a beat-­up cheek bone from hard-­recoiling slugs.

Mossberg 940 JM Pro
The stock is adjustable for cast and length of pull using the supplied and marked spacers. (Photo by Mark Fingar)

Internally, the hard, smooth finish of BN graces many of the critical components including the magazine tube, gas piston, gas ring, hammer and sear. Ease of cleaning is a secondary benefit of the coating. Having it on the parts of the 940’s redesigned gas system ensures reliability.

Some visible changes and other non-­visible changes have been made to the gas operation. Having enlarged gas ports allows reliable use with 1-­ounce shot loads and 7⁄8-­ounce low-­recoiling slugs, vital to 3-­Gunners and recoil-­sensitive shooters. The previous steel spacer tube is replaced with a corrugated, perforated and anodized aluminum spacer. According to Miculek, the new sleeve “provides relief for gasses and debris movement.” The redesigned gas piston redirects hot gasses away from the magazine tube keeping it cleaner. The single piston ring is designed to prevent seizing and is easier to remove for cleaning. Supposedly, the design changes to the gas system means cleaning is required less often.

Fouling of the gas system was a big problem with the outgoing 930. Mossberg says the new self-­cleaning piston may allow firing of up to 1,500 rounds between cleanings. I don’t know that I’d chance it, but those predictions will surely get you through a match or two before you need to get down and dirty. In the words of Mossberg, the 940 JM Pro is “completely redesigned for fast-­paced, reliable cycling in all environmental conditions.”

Mossberg 940 JM Pro
The sliding thumb safety is easy to access by both right- and left-handed shooters. Mossberg’s tang safety is a familiar touch. (Photo by Mark Fingar)

On the range, there were 20 or more guns. After a quick safety briefing, Gunsite instructors allowed Team Miculek to take the lead. Jerry started off with information about cyclic rates and load preference, and after a quick lesson on how to hold the gun to make it do your bidding, Jerry let it rip. I don’t know that he’s capable of firing a single shot, and I suppose doing so would be anticlimactic. What he does do is fire pairs. Jerry shoots pairs so fast you’d swear he’d only fired one shot. He demonstrated that the 940 will cycle as fast as you can fire.

After some showmanship from Jerry, Lena got us on line with our guns. First, we practiced with the new quad-­loaders provided by King Competition (kingcompetitionproducts.com). Lena allowed us to choose between two or four shells at a time based on our ability. I chose to load four. The crisp 5-­pound trigger was clean and quick to reset. Our drill was to shoot two, load two and get back on target as fast as possible. The guns ran well with a mixture of 1-­ounce and 11⁄8-­ounce loads.

After close-­in work and loading, we moved to using slugs. Being optimized to the Miculek slug preference, it was obvious the 940 is a 7⁄8-­ounce slug slinger. At 50 yards, firing the low-­recoil slugs was the equivalent of plinking with a pistol-­caliber carbine. Higher powered, 1,600 feet-­per-­second (fps) slugs of the 1-­ounce variety printed higher because of their speed. Burying the HiViz front sight was the fix to get hits. For Gunsite’s Safari Scrambler, we only fired the 1,600-­fps slugs. Obtaining hits out to 125 yards was simple when I buried the front sight low. With three misses on 14 targets, I figure I could get them all with 7⁄8-­ounce slugs. Gunsite made a great venue for shotgun training. I only wish we had more time.

Mossberg taking another bite at the 3-­Gun-­shotgun apple is cause for other manufacturers to start rethinking their products. For those people who’ve been wanting to try the 3-Gun game, but haven’t because of the shotgun component, you now have a viable option. Knowing the people behind this new shotgun, I’d say that the 940 JM Pro is worth a serious look.

Mossberg 940 JM Pro

  • Type: Gas operated, semiautomatic
  • Gauge: 12
  • Capacity: 9+1 rds.
  • Barrel: 24 in., vent rib
  • Chokes: Briley Accu-Set
  • Overall Length: 44.5 in.
  • Weight: 7 lbs., 12 oz.
  • Sights: HiViz fiber-optic (front); fiber-optic inserts incl.
  • Materials/Finish: Aluminum/anodized; steel/matte blued
  • Stock: Polymer, textured; adj. length of pull, drop at comb, cast and pitch
  • MSRP: $1,015
  • Manufacturer: Mossberg, 203-230-5300, mossberg.com
Current Magazine Cover

Enjoy articles like this?

Subscribe to the magazine.

Get access to everything Guns & Ammo has to offer.
Subscribe to the Magazine

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

First Look: Springfield Armory Model 2020 Waypoint Bolt-Action Rifle

First Look: Springfield Armory Model 2020 Waypoint Bolt-Action Rifle

At the heart of the rifle is the Model 2020 action which wish designed and built with very tight tolerances thanks to Springfield's technology-driven manufacturing capabilities The stainless steel action features an integral recoil lug, and pairs with a fluted bolt employing dual cocking cams and an enhanced extractor for high pressure loads. The blueprinted and precisely machined action allows Springfield to offer the Model 2020 with .75" MOA accuracy guarantee. Despite being a production rifle, the Model 2020 should rival more expensive custom builds.

Red vs. Green Lasers: Visibility in Bright Light

Red vs. Green Lasers: Visibility in Bright Light

In this segment of “At The Range,” Handgunning Editor Jeremy Stafford and contributor Patrick Sweeney compare the visibility of red and green lasers in outdoor, sunny conditions.

Trijicon

Trijicon's New Specialized Reflex Optics (SRO)

The Trijicon SRO is specifically designed for pistol use. The wide field of view and clean, crisp dot makes it easy for users to find and track the dot in both target and competitive shooting applications.

Benelli Lupo Bolt-Action Rifle Review

Benelli Lupo Bolt-Action Rifle Review

It is unlike any other rifle on the market because it offers features no one else does; those looking for a rifle that fits like a custom-made firearm should look no further than the Benelli Lupo.

See More Popular Videos

Trending Articles

In this segment of Air Gun Reviews: Ruger 10/22 Air Rifle Rifles

Air Gun Reviews: Ruger 10/22 Air Rifle

Guns & Ammo Staff - September 02, 2020

In this segment of "Guns & Ammo TV," Gun Tech Editor Richard Nance and Pro-Shooter Jim Tarr...

Whether you're going hunting or to the range, hitting your target is more fun when you have a zeroed rifle scope. Here's how to sight in your rifle scope setup in five quick-and-easy steps.How to Sight In a Rifle Scope in 5 Steps How-To

How to Sight In a Rifle Scope in 5 Steps

Craig Boddington - June 04, 2018

Whether you're going hunting or to the range, hitting your target is more fun when you have a...

The Hornady 6.5 PRC (Precision Rifle Cartridge) is a 6.5 PRC - Magnumized 6.5 Creedmoor Rifle

6.5 PRC - Magnumized 6.5 Creedmoor

Tom Beckstrand - August 01, 2018

The Hornady 6.5 PRC (Precision Rifle Cartridge) is a "magnumized" 6.5 Creedmoor. It offers...

The Savage MSR 15 Competition is an out-of-the-box racehorse ready to help you win 3-Gun matches. Here's why.Savage MSR 15 Competition Review Reviews

Savage MSR 15 Competition Review

James Tarr - May 21, 2019

The Savage MSR 15 Competition is an out-of-the-box racehorse ready to help you win 3-Gun...

See More Trending Articles

More Reviews

The SAKO S20 is a departure from the company's typical offerings, and with change comes a whole lot of options for the consumer.SAKO S20 Rifle Review Reviews

SAKO S20 Rifle Review

Tom Beckstrand - December 01, 2020

The SAKO S20 is a departure from the company's typical offerings, and with change comes a...

Rise Armament's meticulousness turns out some mighty fine rifles, including the 1121XR precision rifle.Rise Armament 1121XR Precision Rifle Review Reviews

Rise Armament 1121XR Precision Rifle Review

Tom Beckstrand - October 12, 2020

Rise Armament's meticulousness turns out some mighty fine rifles, including the 1121XR...

The Savage Arms 110 Elite Precision is an excellent all-around rifle for most shooting activities that don't require light weight. It can be made to fit just about anyone, with a chassis that allows for accurate, rapid and effective positional shooting. And while the 110 Elite Precision is not inexpensive, it still costs less than most custom rifles. Savage Arms 110 Elite Precision Review: Excellent All-Around Rifle Reviews

Savage Arms 110 Elite Precision Review: Excellent All-Around Rifle

Proofhouse - September 15, 2020

The Savage Arms 110 Elite Precision is an excellent all-around rifle for most shooting...

See More Reviews

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE Arrow

Buy Digital Single Issues

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Guns & Ammo App

Other Magazines

See All Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Phone Icon

Get Digital Access.

All Guns and Ammo subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now