Competition Ready Mossberg 940 JM PRO – Review

in Gun Reviews, Jeff Cramblit, Semi-Autos, Shotguns
Competition Ready Mossberg 940 JM PRO - Review
The New 940 JM Pro makes an impressive visual statement before the first shot is even fired.

The new 940 JM PRO shotgun is the latest evolution of Mossberg’s 100-year tradition of producing value-packed firearms at affordable prices. I was lucky enough to spend two days shooting the 940 at Mossberg’s product release event held at the legendary Gunsite Academy. I ran the 940 JM as fast and hard as I could, and it was still ready for more.

As a long-time 3-gun competitor I could truly appreciate all the work they put into the gun that bears the initials of World Champion shooter Jerry Miculek. The features of the 940 JM PRO are tailored to facilitate swift, accurate shooting, and rapid reloading to achieve the fastest times possible in the practical shooting sports where times are recorded to the hundredth of a second.

One of the highlights of the Mossberg Gunsite event was that Jerry and his daughter Lena, who is also a world champion competitor, were there to show us just what the new Mossberg was capable of and give us personalized instruction on our own shooting and loading techniques.

Competition Ready Mossberg 940 JM PRO - Review
Jerry demonstrated exactly what a world-class performance with a shotgun looked like


At first sight, you notice that the 940 JM PRO is a sharp looking gun with a bit of bling to really set it off. The upgrades on this model are many, some are subtle and barely visible, others are more noticeable, but all are important and came from lessons learned or input from their team of world-class shooters.

The most important upgrade from the 930 is a modified gas system to improve reliability and lengthen the interval between needed cleanings. A redesigned gas piston and ring assembly minimizes carbon and lead build-up on the outside of the magazine tube, which has also been upgraded to a Nickel Boron coating to make for smoother operation and easier cleaning.

Competition Ready Mossberg 940 JM PRO - Review
An improved piston and single gas ring are now at the heart of the operating system

The gas piston spacer tube is also redesigned; its shape and vent holes are designed to minimize build-up and provide self-cleaning. Start with a good coat of lubrication and the 940 will run for hundreds of rounds.

The Nitride coating of the piston, piston ring, mag tube, hammer, and sear ensures slicker, smoother operation, and makes cleaning much easier as well. Everything possible has been done to make the 940 a faster operating, more reliable shotgun. Jerry demonstrated just how fast it could run by shooting some .12 second splits during our range time; that equates to 5 shots per second.

The redesigned gas system is now covered by a new slimmer, trimmer handguard that fits the hand well. The polymer handguard now sports a patent-pending Mossberg texture pattern that isn’t overly aggressive but provides just the right level of grip on the shotgun.

Competition Ready Mossberg 940 JM PRO - Review
A detailed look at the new “checkering” pattern found on forearm and grip

The pistol grip area of the buttstock also has the same new texture pattern. More importantly, the improved buttstock is designed to be tailored for fit by the shooter. Anyone who has ever shot skeet or sporting clays knows how important proper fit is in a shotgun, and Mossberg now makes it easier than ever.

The new buttstock has 3 removable spacers to allow adjusting the length of pull from 13” to 14.25”; two .25” spacers and one .5”. The stock is also fitted with a nice soft recoil pad that has been sculpted to minimize the chance of snagging when doing rapid mounts.

Competition Ready Mossberg 940 JM PRO - Review
Stock adjustment spacer system allows adjusting cast and drops independently of each other

Length of Pull (LoP) is only one of the important parts of shotgun fit, but Mossberg didn’t ignore the other more difficult to manipulate ones either. The stock is designed to utilize provided spacers to adjust the drop of the stock and the cast as well.

It comes with a 24” vent rib barrel and a 9 shot extended magazine tube that ends evenly with the barrel. The 24” barrel provides the optimum balance of adequate sight radius for accurate shooting while also being short enough to handle quickly, as needed for rapid target engagement.

The rib and sight height is designed for a 50 yard zero with the reduced recoil slugs typically used in 3-gun competition. This proved to be dead on when we backed out and engaged chest plates from the 50-yard line.

Competition Ready Mossberg 940 JM PRO - Review
Collaborating with industry leaders such as Briley and HIVIZ adds custom features to an affordable shotgun

The barrel is fitted with screw-in choke tubes, but Mossberg went one better and delivers the 940 with three Briley extended choke tubes. Briley Manufacturing has been a provider of premium choke tubes and custom shotgun work for decades. The 3 chokes are Cylinder, Improved Cylinder, and Modified; the most commonly used in 3-gun competitions and probably also for hunting.

To keep the 940 pointed in the right direction the barrel is fitted with a screwed on HIVIZ front sight that comes with multiple fiber optic rods to allow shooters to pick their color and style.

Competition Ready Mossberg 940 JM PRO - Review
Replaceable fiber-optic inserts allow shooters to select based on backgrounds and target size

The 940 JM PRO is fitted with an oversized bolt release and charging handle. These items as well as the safety, trigger, magazine extension nut, and cocking indicator are all anodized for wear resistance and to add a bit of flash to the overall package.

The lightweight aluminum receiver is Type II hard anodized, a matte grey color, adding a bit of contrast and maximizing durability. However, the most important modification is the beveling and enlarging of the loading area at the bottom of the receiver.

Competition Ready Mossberg 940 JM PRO - Review
Redesigned trigger guard, forearm and loading port all support making rapid reloads

In competition and tactical situations, it is critical to be able to reload a shotgun quickly. The new design of the 940 competition-ready loading port and several related components is the most aggressive factory offering available to speed reloads. 

Lena demonstrated that the 940 JM PRO design could be quad loaded in the fashion used by many 3-gun competitors. That’s holding 4 shells in your hand and feeding them in two at a time. Several in the group noted that the rapid loading qualities of the 940 would be great in the field when the skies were full of dove, though you would need a longer magazine plug.

In addition to the enlarged loading port, the trigger guard has been reshaped and the elevator has been enhanced to allow a smooth angle and pinch-free loading.


Gauge                          12

Action                          Gas-piston Semi-Automatic

Overall Length              ~46 inches

Weight                         7.75 lbs

Barrel Length               24 inches

Capacity                       9+1

Sight                            Hiviz Fiber optic on vent rib

Receiver                      Hard Anodized Aluminum

Trigger Weight             5 lbs

MSRP                           $1015

Range Time

After loading and shooting hundreds of rounds of birdshot and more than a few slugs, I have to say I was very impressed with the 940 JM. As with most gas-operated shotguns, recoil was comfortable and very controllable. 

Competition Ready Mossberg 940 JM PRO - Review
Gunsite proved to be an ideal facility to put the 940 JM PRO through all the paces.

I loaded the 940 with my strong hand and my weak hand, loading individual shells, two at a time, and quad loading; the loading port swallowed the shells easily and consistently, so long as I did my part. The extended elevator functioned as designed and never allowed my thumb to be caught while feeding the shells into the magazine tube.

I wasn’t as lightning fast as Jerry, but the 940 proved to be fast shooting, fast loading and was fantastic for shooting splits and engaging multiple targets on the flat range. The set screw in the back of the trigger guard limits over-travel of the trigger and helps make rapid trigger manipulation that much easier.

On the Gunsite Scrambler course, I was able to engage targets beyond 100 yards with slugs while moving between multiple shooting positions and barricades. The smooth 5 lb trigger made shooting the slugs at distant targets feel more like rifle shooting than shotgun shooting.

Competition Ready Mossberg 940 JM PRO - Review
Over-travel stop and the cocked indicator are clearly visible inside the trigger guard.

It doesn’t rain often in the Gunsite area of AZ, but it did just for our event so we could get a real test of the texture of the grip and forearm, and it proved to work perfectly. I never noticed any slippage or any grating of my hands during the two days of shooting.

I was even more impressed with the operating system and recoil pad. They soaked up the recoil from hundreds of rounds ranging from light birdshot, low recoil slugs, several boxes of 1 oz 1600 fps full-power slugs, and I wasn’t bruised or fatigued.

Final Impression

Mossberg went to great lengths to make a shotgun that is ready to compete in the 3-gun arena with no additional work or accessories required and succeeded. The retail price is about what some gunsmiths charge just to modify a shotgun for 3-gun shooting, not counting the price of a gun. Street price for the 940 JM PRO is expected to run from $799 – $899.

Competition Ready Mossberg 940 JM PRO - Review
The anodized receiver is tapped for adding optics for those wanting to shoot Open-division.

I would expect to pay much more for a shotgun that looks, shoots, and has as many features as the 940 JM PRO. You won’t find a competition-ready gun that offers as much value for your money as the Mossberg 940 JM PRO.

For more information visit Mossberg website.

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