“Specialized weapons need specialized ammunition.”

The term Next Generation can mean a lot of things. I recently wrote an article on U.S. Army Next Generation 40mm Day/Night Thermal training ammunition technology. The results are still “to be determined.” I took a hard look at some Next Generation weapons and ammunition in this article. What happens when Next Generation weapons and ammo collide?

Maxim Defense’s PDX Pistol in .300 BLK.

Maxim Defense continues to impress with its Next Generation focus and out-of-the-box thinking. Maxim Defense’s short-barreled rifle (SBR) designs are impressive and enthralling enough to be selected by SOCOM for further evaluations. Its success with the U.S. government has carried over to the commercial market with personal defense weapons (PDWs). Commercially, the weapons also have gained a following in the personal defensive arena and in the concealed weapon subcategory of untold possibilities.

I first got my hands on one of these weapons at the 2019 Special Operations Forces Industry Conference (SOFIC). Ammunition and guns are in surprisingly short supply at SOFIC, as the focus is much more on electronics. I was drawn like a moth to the flame.

The weapons are as visually impressive as they are physically stout and well-engineered. The construction is remarkable; some AR platform weapons feel flimsy. The Maxim rifles remind me of HK weapons. The 18.75-inch weapon overall length is impressive, and the punch packed by these weapons blows pistols out of the water. The 5.5-inch barrel length is also amazing. If you add in the massive increase in accuracy over a pistol and the potential magazine capacity, I imagine that many private security forces are in line to grab these SBRs and re-arm their teams.

What About the Ammo?

Defensive pistol ammunition is numerous and widespread. Defensive rifle ammunition, not so much. All the major ammunition producers have versions of defensive pistol ammunition, and the number of niche producers is also a mile long. Many designs go beyond the typical hollow-point designs. There have been more niche designs going back over the last 40-plus years than I can remember. Who remembers the big left-wing hysteria concerning the Black Talon bullets back in the early 1990s? More recently, G2 Research Ammunitions’ fragmenting solid bullets were a big item and huge YouTube sensation. Maxim Defense knew that the weapons needed special rifle ammunition to pair with these very special rifles. The company could have gone with one of the usual suspect bullets in rifle calibers. Instead, Maxim went a whole new direction. In retrospect, it seems only logical that a Next Generation defensive rifle would have its personalized Next Generation defensive ammunition.

Maxim has a truly innovative rifle ammunition product that works superbly in these SBRs. Specialized weapons need specialized ammunition to fully capitalize on the performance limitations of lower velocities with short barrels. The Maxim Defense team saw that if customers did not use the proper ammunition, the effectiveness of the weapons would be massively diminished. To complete Maxim’s total weapon system, the ammunition needed to be the Next Generation to maximize the performance needs exactly specified and to be available to the customers. There are some potential solutions in the marketplace; however, consistent access to the customer is always difficult with niche products. Just as high-performance engines will barely work on low-octane gas, these SBRs need high octane ammo, and Maxim took charge of the situation.

TUI® Projectiles

Fort Scott Munitions™ (FSM®) and Maxim Defense worked together on a 6.5CM project for the U.S. government. Upon starting this relationship, Maxim Defense approached FSM to build and optimize a full-ammo solution for the SBR in critically short-barrel lengths for the PDX and MDX Weapon Lines. Six separate ammo variants were designed and optimized; FSM is Maxim Defense’s Original Equipment Manufacturer (OEM).

TUI® in 5.56 NATO.

It was not enough to just take one of the top defensive rifle bullets and load it. Maxim Defense knew that the FSM had developed something special with their Tumble Upon Impact™ (TUI®) projectiles. The TUI projectiles are patented Next Generation technology, just like the Maxim rifles. These TUI projectiles increase the effectiveness of Maxim’s weapon system and accomplish impressive terminal ballistic cavities without substantial fragmentation all the way down to minimal velocities and/or until they become unstable.

The impressive part of the TUI projectiles is that they have a solid tip without any flutes/grooves/slots or other special effects that might impede the successful feeding, firing and cycling out of the weapon. These will hold up and function in extreme environments. They surpass the criteria of both expanding and fragmenting projectiles in ballistic gel. These designs and features are only more critical in rifle calibers. Maxim has successfully achieved a winning combination of weapon and ammunition.

These solid copper projectiles appear to maintain extremely high percentages of their initial weight in the pistol ammunition. Many tests indicate 100% retention through ballistic gels. This ensures greater energy transfer, consistency in performance and devastating wound channels. Monolithic solids are great for not having a jacket to separate from the core, which is also very important in close-combat situations where the fragments can be a hazard to the shooter. The projectile stays together in one piece, causes significant damage and gives more knockdown power. The testing for the rifle ammunition appears to have very similar results to the pistol ammunition.

The short barrel ammunition comes in three calibers and six total varieties:

Caliber Projectile Weight (gr)
5.56 NATO 55
5.56 NATO 62
5.56 NATO 70
7.62x39mm 117
.300 Blackout Supersonic 115
.300 Blackout Subsonic 190

The projectiles being made out of 100% copper also add a nice element of being lead-free. This is ideal for the close-combat training scenarios in which this product will be used. This also opens up use in lead-restricted ranges and states around the country. All the ammo is Match Grade.

After some R&D, FSM recalled the old 5.56mm M855 round that sometimes accidentally tumbled or keyholed. This failure was a huge problem for the M855. However, a tumbling defensive bullet could offer some impressive performance if done right. What if they could make this happen on purpose and with 100% consistency? This would make for some very effective defensive ammunition. They started working on the concept and came up with two patents.


Some elements must be considered: First, it is not a traditional FMJ, and it only tumbles on water-based solutions (i.e., water jugs, ballistic gelatin). If it is fired into a wood 2×4, metal, drywall or vehicle windshield, it will not tumble—period. However, for their key customer and the defensive ammo market, these were acceptable parameters.

The energy released because of the tumble is impressive. This is because of multiple elements. First, the bullets have 100% weight retention. With no loss of mass from fragments shedding, the energy is retained. Second, in ballistic gelatin, the projectile will tumble and then briefly stabilize and stay on its trajectory. Then, it will start to tumble for a bit and then track straight again. FSM noted, “Typically, the projectile will get two to three ‘tumble then brief stabilization’ cycles in a 6x6x16-inch-long ballistic gelatin block.” Impressive.

TUI comes in two different materials. The first is solid brass, and the second is copper. The brass version is called “solid brass spun” or SBS. The copper version is similarly “solid copper spun” or SCS. FSM also has a full line of brass projectiles in pistol calibers (.45, 9mm, .40 S&W, 10mm, .380, .357 SIG) that are only LE/military.

The product is well-designed and versatile. It is not a one-trick pony. Ultimate versatility is an objective FSM strived to achieve with the TUI ammunition. They believe the TUI ammo is a great military or law enforcement round. It checks all the boxes: it goes through the barrier, has great accuracy and has an excellent performance in ballistic gel. However, with the same ammunition, you can also go hunting for coyote and even buffalo. Better yet, it has great long-range utility. An FSM employee recently used his 6.5 Creedmoor, 123-grain, TUI factory-boxed ammunition to take a deer at 100 yards (and dropped him cold), and the same round is capable of a distance of 1.39 miles (2,446.4 yards) to hit a 30-inch target twice on a string of 10 with a factory Ruger Precision Rifle (see YouTube video at Longshot Video). Yes, the TUI projectile is still stable out at that distance, despite tumbling in ballistic gelatin. TUI is the complete package—self-defense, hunting and long-range performance.

A key aspect of the ammunition is that there is no mechanical feature to rely on, nothing to fail. So many of the other high-performance bullets are counting on the consistency of the tooling and keeping a close eye on tooling wear and performance. Of course, this means that the bullets made on fresh tooling are going to perform slightly differently than the last rounds before a tool change. I am aware that some of these performance bullets could require tool change in as little as 5,000 to 10,000 rounds manufactured. This all happens on a multi-station transfer press that is running at 60 parts per minute—no small task.

I queried on what feature of the bullet and the bullet design is critical. The answer is not just one thing. It is everything—the tip, the ogive and the boat tail. It can take strenuous testing and a lot of time to develop a single round. It took 1 year to develop the .300 Blackout 190 subsonic. It is one of the few truly subsonic rounds at +/- 950 to 960 fps. It will also function without a suppressor on the Maxim Defense SBR weapons.

Maxim Defense’s PDX and MDX Weapon Lines and FSM’s TUI® ammo.

Superior Weapon System

Maxim Defense produces high-quality firearms that enhance their ammo and make it perform well. The quality of FSM’s ammo and the weapons mesh so well, they result in an overall superior weapon system. I suspect that both Maxim Defense and Fort Scott Munitions are going to be long-term players in the market.

So, what happens when Next Generation weapons and ammo collide? Nothing short of awesome.